diff --git a/app/assets/javascripts/admin/models/admin_user.js b/app/assets/javascripts/admin/models/admin_user.js
index d005c14523..7e66e278ab 100644
--- a/app/assets/javascripts/admin/models/admin_user.js
+++ b/app/assets/javascripts/admin/models/admin_user.js
@@ -328,6 +328,48 @@ Discourse.AdminUser = Discourse.User.extend({
     });
   },
 
+  anonymizeForbidden: Em.computed.not("can_be_anonymized"),
+
+  anonymize: function() {
+    var user = this;
+
+    var performAnonymize = function() {
+      Discourse.ajax("/admin/users/" + user.get('id') + '/anonymize.json', {type: 'PUT'}).then(function(data) {
+        if (data.success) {
+          bootbox.alert(I18n.t("admin.user.anonymize_successful"));
+          if (data.username) {
+            document.location = "/admin/users/" + data.username;
+          } else {
+            document.location = "/admin/users/list/active";
+          }
+        } else {
+          bootbox.alert(I18n.t("admin.user.anonymize_failed"));
+          if (data.user) {
+            user.setProperties(data.user);
+          }
+        }
+      }, function() {
+        bootbox.alert(I18n.t("admin.user.anonymize_failed"));
+      });
+    };
+
+    var message = I18n.t("admin.user.anonymize_confirm");
+
+    var buttons = [{
+      "label": I18n.t("composer.cancel"),
+      "class": "cancel",
+      "link":  true
+    }, {
+      "label": '<i class="fa fa-exclamation-triangle"></i>' + I18n.t('admin.user.anonymize_yes'),
+      "class": "btn btn-danger",
+      "callback": function(){
+        performAnonymize();
+      }
+    }];
+
+    bootbox.dialog(message, buttons, {"classes": "delete-user-modal"});
+  },
+
   deleteForbidden: Em.computed.not("canBeDeleted"),
 
   deleteExplanation: function() {
diff --git a/app/assets/javascripts/admin/templates/user_index.hbs b/app/assets/javascripts/admin/templates/user_index.hbs
index 6c85c515eb..bd25465e13 100644
--- a/app/assets/javascripts/admin/templates/user_index.hbs
+++ b/app/assets/javascripts/admin/templates/user_index.hbs
@@ -450,6 +450,11 @@
 
 <section>
   <hr/>
+  <button {{bind-attr class=":btn :btn-danger :pull-right anonymizeForbidden:hidden"}} {{action "anonymize" target="content"}} {{bind-attr disabled="anonymizeForbidden"}}>
+    <i class="fa fa-exclamation-triangle"></i>
+    {{i18n 'admin.user.anonymize'}}
+  </button>
+
   <button {{bind-attr class=":btn :btn-danger :pull-right deleteForbidden:hidden"}} {{action "destroy" target="content"}} {{bind-attr disabled="deleteForbidden"}}>
     <i class="fa fa-exclamation-triangle"></i>
     {{i18n 'admin.user.delete'}}
diff --git a/app/controllers/admin/users_controller.rb b/app/controllers/admin/users_controller.rb
index c0f2469524..c1194709f5 100644
--- a/app/controllers/admin/users_controller.rb
+++ b/app/controllers/admin/users_controller.rb
@@ -22,7 +22,8 @@ class Admin::UsersController < Admin::AdminController
                                     :remove_group,
                                     :primary_group,
                                     :generate_api_key,
-                                    :revoke_api_key]
+                                    :revoke_api_key,
+                                    :anonymize]
 
   def index
     users = ::AdminUserIndexQuery.new(params).find_users
@@ -333,6 +334,15 @@ class Admin::UsersController < Admin::AdminController
 
   end
 
+  def anonymize
+    guardian.ensure_can_anonymize_user!(@user)
+    if user = UserAnonymizer.new(@user, current_user).make_anonymous
+      render json: success_json.merge(username: user.username)
+    else
+      render json: failed_json.merge(user: AdminDetailedUserSerializer.new(user, root: false).as_json)
+    end
+  end
+
   private
 
     def fetch_user
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 98b4e3911b..d257cb7e2d 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -93,7 +93,7 @@ class UsersController < ApplicationController
     guardian.ensure_can_edit_username!(user)
 
     # TODO proper error surfacing (result is a Model#save call)
-    result = user.change_username(params[:new_username], current_user)
+    result = UsernameChanger.change(user, params[:new_username], current_user)
     raise Discourse::InvalidParameters.new(:new_username) unless result
 
     render json: {
diff --git a/app/models/user.rb b/app/models/user.rb
index 8308ad5efb..34eb40a880 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -187,12 +187,7 @@ class User < ActiveRecord::Base
   end
 
   def change_username(new_username, actor=nil)
-    if actor && actor != self
-      StaffActionLogger.new(actor).log_username_change(self, self.username, new_username)
-    end
-
-    self.username = new_username
-    save
+    UsernameChanger.change(self, new_username, actor)
   end
 
   def created_topic_count
@@ -716,6 +711,10 @@ class User < ActiveRecord::Base
     UserHistory.for(self, :suspend_user).count
   end
 
+  def create_user_profile
+    UserProfile.create(user_id: id)
+  end
+
   protected
 
   def badge_grant
@@ -734,10 +733,6 @@ class User < ActiveRecord::Base
     end
   end
 
-  def create_user_profile
-    UserProfile.create(user_id: id)
-  end
-
   def ensure_in_trust_level_group
     Group.user_trust_level_change!(id, trust_level)
   end
diff --git a/app/models/user_history.rb b/app/models/user_history.rb
index ffe75d2487..3fe017d69a 100644
--- a/app/models/user_history.rb
+++ b/app/models/user_history.rb
@@ -37,7 +37,8 @@ class UserHistory < ActiveRecord::Base
                           :roll_up,
                           :change_username,
                           :custom,
-                          :custom_staff)
+                          :custom_staff,
+                          :anonymize_user)
   end
 
   # Staff actions is a subset of all actions, used to audit actions taken by staff users.
@@ -57,7 +58,8 @@ class UserHistory < ActiveRecord::Base
                         :impersonate,
                         :roll_up,
                         :change_username,
-                        :custom_staff]
+                        :custom_staff,
+                        :anonymize_user]
   end
 
   def self.staff_action_ids
diff --git a/app/serializers/admin_detailed_user_serializer.rb b/app/serializers/admin_detailed_user_serializer.rb
index 3646ccd210..02c84bd000 100644
--- a/app/serializers/admin_detailed_user_serializer.rb
+++ b/app/serializers/admin_detailed_user_serializer.rb
@@ -15,6 +15,7 @@ class AdminDetailedUserSerializer < AdminUserSerializer
              :private_topics_count,
              :can_delete_all_posts,
              :can_be_deleted,
+             :can_be_anonymized,
              :suspend_reason,
              :primary_group_id,
              :badge_count,
@@ -51,6 +52,10 @@ class AdminDetailedUserSerializer < AdminUserSerializer
     scope.can_delete_user?(object)
   end
 
+  def can_be_anonymized
+    scope.can_anonymize_user?(object)
+  end
+
   def moderator
     object.moderator
   end
diff --git a/app/services/user_anonymizer.rb b/app/services/user_anonymizer.rb
new file mode 100644
index 0000000000..5225326dce
--- /dev/null
+++ b/app/services/user_anonymizer.rb
@@ -0,0 +1,63 @@
+class UserAnonymizer
+  def initialize(user, actor=nil)
+    @user = user
+    @actor = actor
+  end
+
+  def self.make_anonymous(user, actor=nil)
+    self.new(user, actor).make_anonymous
+  end
+
+  def make_anonymous
+    User.transaction do
+      prev_email = @user.email
+      prev_username = @user.username
+
+      if !UsernameChanger.change(@user, make_anon_username)
+        raise "Failed to change username"
+      end
+
+      @user.reload
+      @user.password = SecureRandom.hex
+      @user.email = "#{@user.username}@example.com"
+      @user.name = nil
+      @user.date_of_birth = nil
+      @user.title = nil
+      @user.email_digests = false
+      @user.email_private_messages = false
+      @user.email_direct = false
+      @user.email_always = false
+      @user.mailing_list_mode = false
+      @user.save
+
+      profile = @user.user_profile
+      profile.destroy if profile
+      @user.create_user_profile
+
+      @user.user_avatar.try(:destroy)
+      @user.twitter_user_info.try(:destroy)
+      @user.google_user_info.try(:destroy)
+      @user.github_user_info.try(:destroy)
+      @user.facebook_user_info.try(:destroy)
+      @user.single_sign_on_record.try(:destroy)
+      @user.oauth2_user_info.try(:destroy)
+      @user.user_open_ids.find_each { |x| x.destroy }
+      @user.api_key.try(:destroy)
+
+      UserHistory.create( action: UserHistory.actions[:anonymize_user],
+                          target_user_id: @user.id,
+                          acting_user_id: @actor ? @actor.id : @user.id,
+                          email: prev_email,
+                          details: "username: #{prev_username}" )
+    end
+    @user
+  end
+
+  def make_anon_username
+    100.times do
+      new_username = "anon#{(SecureRandom.random_number * 100000000).to_i}"
+      return new_username unless User.where(username_lower: new_username).exists?
+    end
+    raise "Failed to generate an anon username"
+  end
+end
diff --git a/app/services/username_changer.rb b/app/services/username_changer.rb
new file mode 100644
index 0000000000..00a1df62b4
--- /dev/null
+++ b/app/services/username_changer.rb
@@ -0,0 +1,23 @@
+class UsernameChanger
+
+  def initialize(user, new_username, actor=nil)
+    @user = user
+    @new_username = new_username
+    @actor = actor
+  end
+
+  def self.change(user, new_username, actor=nil)
+    self.new(user, new_username, actor).change
+  end
+
+  def change
+    if @actor && @actor != @user
+      StaffActionLogger.new(@actor).log_username_change(@user, @user.username, @new_username)
+    end
+
+    # future work: update mentions and quotes
+
+    @user.username = @new_username
+    @user.save
+  end
+end
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index 5737965848..900716fb8b 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -1912,6 +1912,7 @@ en:
             delete_topic: "delete topic"
             delete_post: "delete post"
             impersonate: "impersonate"
+            anonymize_user: "anonymize user"
         screened_emails:
           title: "Screened Emails"
           description: "When someone tries to create a new account, the following email addresses will be checked and the registration will be blocked, or some other action performed."
@@ -2048,6 +2049,11 @@ en:
         approve_success: "User approved and email sent with activation instructions."
         approve_bulk_success: "Success! All selected users have been approved and notified."
         time_read: "Read Time"
+        anonymize: "Anonymize User"
+        anonymize_confirm: "Are you SURE you want to anonymize this account? This will change the username and email, and reset all profile information."
+        anonymize_yes: "Yes, anonymize this account"
+        anonymize_successful: "The user was anonymized successfully."
+        anonymize_failed: "There was a problem anonymizing the account."
         delete: "Delete User"
         delete_forbidden_because_staff: "Admins and moderators can't be deleted."
         delete_posts_forbidden_because_staff: "Can't delete all posts of admins and moderators."
diff --git a/config/routes.rb b/config/routes.rb
index 971c7591df..a1d38c8fb6 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -96,6 +96,7 @@ Discourse::Application.routes.draw do
       get "badges"
       get "leader_requirements" => "users#tl3_requirements"
       get "tl3_requirements"
+      put "anonymize"
     end
 
 
diff --git a/lib/guardian/user_guardian.rb b/lib/guardian/user_guardian.rb
index 6c0206d525..f67f494108 100644
--- a/lib/guardian/user_guardian.rb
+++ b/lib/guardian/user_guardian.rb
@@ -47,6 +47,10 @@ module UserGuardian
     end
   end
 
+  def can_anonymize_user?(user)
+    is_staff? && !user.nil? && !user.staff?
+  end
+
   def can_check_emails?(user)
     is_admin? || (is_staff? && SiteSetting.show_email_on_profile)
   end
diff --git a/spec/components/guardian_spec.rb b/spec/components/guardian_spec.rb
index 6cb9eaf3bc..4431ccf593 100644
--- a/spec/components/guardian_spec.rb
+++ b/spec/components/guardian_spec.rb
@@ -1585,6 +1585,48 @@ describe Guardian do
     end
   end
 
+  describe "can_anonymize_user?" do
+    it "is false without a logged in user" do
+      expect(Guardian.new(nil).can_anonymize_user?(user)).to be_falsey
+    end
+
+    it "is false without a user to look at" do
+      expect(Guardian.new(admin).can_anonymize_user?(nil)).to be_falsey
+    end
+
+    it "is false for a regular user" do
+      expect(Guardian.new(user).can_anonymize_user?(coding_horror)).to be_falsey
+    end
+
+    it "is false for myself" do
+      expect(Guardian.new(user).can_anonymize_user?(user)).to be_falsey
+    end
+
+    it "is true for admin anonymizing a regular user" do
+      Guardian.new(admin).can_anonymize_user?(user).should == true
+    end
+
+    it "is true for moderator anonymizing a regular user" do
+      Guardian.new(moderator).can_anonymize_user?(user).should == true
+    end
+
+    it "is false for admin anonymizing an admin" do
+      expect(Guardian.new(admin).can_anonymize_user?(Fabricate(:admin))).to be_falsey
+    end
+
+    it "is false for admin anonymizing a moderator" do
+      expect(Guardian.new(admin).can_anonymize_user?(Fabricate(:moderator))).to be_falsey
+    end
+
+    it "is false for moderator anonymizing an admin" do
+      expect(Guardian.new(moderator).can_anonymize_user?(admin)).to be_falsey
+    end
+
+    it "is false for moderator anonymizing a moderator" do
+      expect(Guardian.new(moderator).can_anonymize_user?(Fabricate(:moderator))).to be_falsey
+    end
+  end
+
   describe 'can_grant_title?' do
     it 'is false without a logged in user' do
       expect(Guardian.new(nil).can_grant_title?(user)).to be_falsey
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 71858f1092..95e32d837a 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -97,92 +97,6 @@ describe User do
     end
   end
 
-  describe 'change_username' do
-
-    let(:user) { Fabricate(:user) }
-
-    context 'success' do
-      let(:new_username) { "#{user.username}1234" }
-
-      before do
-        @result = user.change_username(new_username)
-      end
-
-      it 'returns true' do
-        expect(@result).to eq(true)
-      end
-
-      it 'should change the username' do
-        user.reload
-        expect(user.username).to eq(new_username)
-      end
-
-      it 'should change the username_lower' do
-        user.reload
-        expect(user.username_lower).to eq(new_username.downcase)
-      end
-    end
-
-    context 'failure' do
-      let(:wrong_username) { "" }
-      let(:username_before_change) { user.username }
-      let(:username_lower_before_change) { user.username_lower }
-
-      before do
-        @result = user.change_username(wrong_username)
-      end
-
-      it 'returns false' do
-        expect(@result).to eq(false)
-      end
-
-      it 'should not change the username' do
-        user.reload
-        expect(user.username).to eq(username_before_change)
-      end
-
-      it 'should not change the username_lower' do
-        user.reload
-        expect(user.username_lower).to eq(username_lower_before_change)
-      end
-    end
-
-    describe 'change the case of my username' do
-      let!(:myself) { Fabricate(:user, username: 'hansolo') }
-
-      it 'should return true' do
-        expect(myself.change_username('HanSolo')).to eq(true)
-      end
-
-      it 'should change the username' do
-        myself.change_username('HanSolo')
-        expect(myself.reload.username).to eq('HanSolo')
-      end
-    end
-
-    describe 'allow custom minimum username length from site settings' do
-      before do
-        @custom_min = 2
-        SiteSetting.min_username_length = @custom_min
-      end
-
-      it 'should allow a shorter username than default' do
-        result = user.change_username('a' * @custom_min)
-        expect(result).not_to eq(false)
-      end
-
-      it 'should not allow a shorter username than limit' do
-        result = user.change_username('a' * (@custom_min - 1))
-        expect(result).to eq(false)
-      end
-
-      it 'should not allow a longer username than limit' do
-        result = user.change_username('a' * (User.username_length.end + 1))
-        expect(result).to eq(false)
-      end
-    end
-  end
-
   describe 'delete posts' do
     before do
       @post1 = Fabricate(:post)
diff --git a/spec/services/user_anonymizer_spec.rb b/spec/services/user_anonymizer_spec.rb
new file mode 100644
index 0000000000..40ac4bddd6
--- /dev/null
+++ b/spec/services/user_anonymizer_spec.rb
@@ -0,0 +1,99 @@
+require "spec_helper"
+
+describe UserAnonymizer do
+
+  describe "make_anonymous" do
+    let(:admin) { Fabricate(:admin) }
+    let(:user) { Fabricate(:user, username: "edward") }
+
+    subject(:make_anonymous) { described_class.make_anonymous(user, admin) }
+
+    it "changes username" do
+      make_anonymous
+      user.reload.username.should =~ /^anon\d{3,}$/
+    end
+
+    it "changes email address" do
+      make_anonymous
+      user.reload.email.should == "#{user.username}@example.com"
+    end
+
+    it "turns off all notifications" do
+      make_anonymous
+      user.reload
+      user.email_digests.should == false
+      user.email_private_messages.should == false
+      user.email_direct.should == false
+      user.email_always.should == false
+      user.mailing_list_mode.should == false
+    end
+
+    it "resets profile to default values" do
+      user.update_attributes( name: "Bibi", date_of_birth: 19.years.ago, title: "Super Star" )
+
+      profile = user.user_profile(true)
+      profile.update_attributes( location: "Moose Jaw",
+                                 website: "www.bim.com",
+                                 bio_raw: "I'm Bibi from Moosejaw. I sing and dance.",
+                                 bio_cooked: "I'm Bibi from Moosejaw. I sing and dance.",
+                                 profile_background: "http://example.com/bg.jpg",
+                                 bio_cooked_version: 2,
+                                 card_background: "http://example.com/cb.jpg")
+      make_anonymous
+      user.reload
+
+      user.name.should_not be_present
+      user.date_of_birth.should == nil
+      user.title.should_not be_present
+
+      profile = user.user_profile(true)
+      profile.location.should == nil
+      profile.website.should == nil
+      profile.bio_cooked.should == nil
+      profile.profile_background.should == nil
+      profile.bio_cooked_version.should == nil
+      profile.card_background.should == nil
+    end
+
+    it "removes the avatar" do
+      upload = Fabricate(:upload, user: user)
+      user.user_avatar = UserAvatar.new(user_id: user.id, custom_upload_id: upload.id)
+      user.save!
+      expect { make_anonymous }.to change { Upload.count }.by(-1)
+      user.reload
+      user.user_avatar.should == nil
+    end
+
+    it "logs the action" do
+      expect { make_anonymous }.to change { UserHistory.count }.by(1)
+    end
+
+    it "removes external auth assocations" do
+      user.twitter_user_info = TwitterUserInfo.create(user_id: user.id, screen_name: "example", twitter_user_id: "examplel123123")
+      user.google_user_info = GoogleUserInfo.create(user_id: user.id, google_user_id: "google@gmail.com")
+      user.github_user_info = GithubUserInfo.create(user_id: user.id, screen_name: "example", github_user_id: "examplel123123")
+      user.facebook_user_info = FacebookUserInfo.create(user_id: user.id, facebook_user_id: "example")
+      user.single_sign_on_record = SingleSignOnRecord.create(user_id: user.id, external_id: "example", last_payload: "looks good")
+      user.oauth2_user_info = Oauth2UserInfo.create(user_id: user.id, uid: "example", provider: "example")
+      UserOpenId.create(user_id: user.id, email: user.email, url: "http://example.com/openid", active: true)
+      make_anonymous
+      user.reload
+      user.twitter_user_info.should == nil
+      user.google_user_info.should == nil
+      user.github_user_info.should == nil
+      user.facebook_user_info.should == nil
+      user.single_sign_on_record.should == nil
+      user.oauth2_user_info.should == nil
+      user.user_open_ids.count.should == 0
+    end
+
+    it "removes api key" do
+      ApiKey.create(user_id: user.id, key: "123123123")
+      expect { make_anonymous }.to change { ApiKey.count }.by(-1)
+      user.reload
+      user.api_key.should == nil
+    end
+
+  end
+
+end
diff --git a/spec/services/username_changer_spec.rb b/spec/services/username_changer_spec.rb
new file mode 100644
index 0000000000..debbf70cad
--- /dev/null
+++ b/spec/services/username_changer_spec.rb
@@ -0,0 +1,90 @@
+require 'spec_helper'
+
+describe UsernameChanger do
+
+  describe '#change' do
+    let(:user) { Fabricate(:user) }
+
+    context 'success' do
+      let(:new_username) { "#{user.username}1234" }
+
+      before do
+        @result = described_class.change(user, new_username)
+      end
+
+      it 'returns true' do
+        expect(@result).to eq(true)
+      end
+
+      it 'should change the username' do
+        user.reload
+        expect(user.username).to eq(new_username)
+      end
+
+      it 'should change the username_lower' do
+        user.reload
+        expect(user.username_lower).to eq(new_username.downcase)
+      end
+    end
+
+    context 'failure' do
+      let(:wrong_username) { "" }
+      let(:username_before_change) { user.username }
+      let(:username_lower_before_change) { user.username_lower }
+
+      before do
+        @result = described_class.change(user, wrong_username)
+      end
+
+      it 'returns false' do
+        expect(@result).to eq(false)
+      end
+
+      it 'should not change the username' do
+        user.reload
+        expect(user.username).to eq(username_before_change)
+      end
+
+      it 'should not change the username_lower' do
+        user.reload
+        expect(user.username_lower).to eq(username_lower_before_change)
+      end
+    end
+
+    describe 'change the case of my username' do
+      let!(:myself) { Fabricate(:user, username: 'hansolo') }
+
+      it 'should return true' do
+        expect(described_class.change(myself, "HanSolo")).to eq(true)
+      end
+
+      it 'should change the username' do
+        described_class.change(myself, "HanSolo")
+        expect(myself.reload.username).to eq('HanSolo')
+      end
+    end
+
+    describe 'allow custom minimum username length from site settings' do
+      before do
+        @custom_min = 2
+        SiteSetting.min_username_length = @custom_min
+      end
+
+      it 'should allow a shorter username than default' do
+        result = described_class.change(user, 'a' * @custom_min)
+        expect(result).not_to eq(false)
+      end
+
+      it 'should not allow a shorter username than limit' do
+        result = described_class.change(user, 'a' * (@custom_min - 1))
+        expect(result).to eq(false)
+      end
+
+      it 'should not allow a longer username than limit' do
+        result = described_class.change(user, 'a' * (User.username_length.end + 1))
+        expect(result).to eq(false)
+      end
+    end
+  end
+
+end