diff --git a/app/controllers/answers_controller.rb b/app/controllers/answers_controller.rb
index c72174d..83f4e62 100644
--- a/app/controllers/answers_controller.rb
+++ b/app/controllers/answers_controller.rb
@@ -1,6 +1,7 @@
 class AnswersController < ApplicationController
   before_action :set_question
   before_action :set_answer, only: [:show, :update, :destroy]
+  include OwnershipConcern
 
   def index
     @answers = @question.answers.all
@@ -14,11 +15,12 @@ def show
 
   def create
     @answer = @question.answers.new(answer_params)
+    @answer.user = current_user
 
     if @answer.save
       render json: @answer, status: :created, location: question_answer_path(@question, @answer)
     else
-      render json: @answer.errors, status: :unprocessable_entity
+      invalid_request(error_msg)
     end
   end
 
@@ -26,13 +28,16 @@ def update
     if @answer.update(answer_params)
       head :no_content
     else
-      render json: @answer.errors, status: :unprocessable_entity
+      invalid_request(error_msg)
     end
   end
 
   def destroy
-    @answer.destroy
-    head :no_content
+    if @answer.try(:destroy)
+      head :no_content
+    else
+      invalid_request(error_msg)
+    end
   end
 
   private
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index c597c78..a2ea850 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -34,6 +34,11 @@ def unauthorized_token
     render json: {errors: "Request was made with invalid token"}, status: 401
   end
 
+  def error_msg
+    "The operation could not be performed."\
+    " Please check your request or try again later"
+  end
+
 
   def set_attrs_in_session(hash={})
     hash.each do |key, val|
diff --git a/app/controllers/concerns/ownership_concern.rb b/app/controllers/concerns/ownership_concern.rb
new file mode 100644
index 0000000..537e116
--- /dev/null
+++ b/app/controllers/concerns/ownership_concern.rb
@@ -0,0 +1,27 @@
+
+require 'forwardable'
+module OwnershipConcern
+  extend ActiveSupport::Concern
+
+  included do
+    extend Forwardable
+    def_delegator self, :resource_name
+    def self.resource_name
+      controller_name.singularize
+    end
+
+    before_action "check_user_owns_#{resource_name}", only: [:update, :destroy]
+
+    define_method "check_user_owns_#{resource_name}" do
+      resource = instance_variable_get("@#{resource_name}")
+      if resource
+        unauthorized_access && return unless resource.user == current_user
+      end
+    end
+  end
+
+  def unauthorized_access
+    render json: {errors: "Unauthorized/Forbidden Access: #{resource_name.capitalize} does not belong to user"}, status: :forbidden
+  end
+
+end
diff --git a/app/controllers/questions_controller.rb b/app/controllers/questions_controller.rb
index 2a7519c..e5f1d02 100644
--- a/app/controllers/questions_controller.rb
+++ b/app/controllers/questions_controller.rb
@@ -1,6 +1,7 @@
 class QuestionsController < ApplicationController
   before_action :set_question, only: [:show, :update, :destroy]
   before_action :authenticate_user
+
   def index
     questions = Question.all
     render json: questions, status: 200
@@ -48,11 +49,6 @@ def set_question
     resource_not_found && return unless @question
   end
 
-  def error_msg
-    "The operation could not be performed."\
-    " Please check your request or try again later"
-  end
-
   def questions_params
     params.permit(:id, :title, :content, :votes)
   end
diff --git a/app/controllers/tokens_controller.rb b/app/controllers/tokens_controller.rb
index 631310a..67f8d3b 100644
--- a/app/controllers/tokens_controller.rb
+++ b/app/controllers/tokens_controller.rb
@@ -9,7 +9,7 @@ def validate
 
   private
     def set_token
-      @token = Token.active.find_by(temp: params[:temp_token]).destroy
+      @token = Token.active.find_by(temp: params[:temp_token]).try(:destroy)
       resource_not_found unless @token
     end
 end
diff --git a/app/models/concerns/andela_validator.rb b/app/models/concerns/andela_validator.rb
new file mode 100644
index 0000000..957823c
--- /dev/null
+++ b/app/models/concerns/andela_validator.rb
@@ -0,0 +1,9 @@
+module AndelaValidator
+  extend ActiveSupport::Concern
+
+  ANDELA_EMAIL_REGEX = /[\w.]+@andela.co[m]?\z/
+  included do
+    validates :email, presence: true, format: {with: ANDELA_EMAIL_REGEX, message: "Sign in with an Andela email address"}
+  end
+
+end
diff --git a/app/models/social_provider.rb b/app/models/social_provider.rb
index a074195..bb9c98a 100644
--- a/app/models/social_provider.rb
+++ b/app/models/social_provider.rb
@@ -1,4 +1,5 @@
 class SocialProvider < ActiveRecord::Base
+  include AndelaValidator
   belongs_to :user
   validates :uuid, presence: true
   validates :provider, presence: true
diff --git a/app/models/user.rb b/app/models/user.rb
index fb5060b..4f6aa2c 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,13 +1,18 @@
 class User < ActiveRecord::Base
+  include AndelaValidator
   has_many :comments, as: :comment_on
   has_many :tags, as: :subscriber
   has_many :questions
   has_many :answers
   has_many :social_providers
   has_many :tokens
+  EMAIL_FORMAT= /(?<email>[.\w]+@andela).co[m]?\z/
 
   def self.from_omniauth(auth, user=nil)
-    user = where(email: auth.info.email).first_or_create do |u|
+    email_address = auth.info.email
+    grabbed = EMAIL_FORMAT.match(email_address).try(:[], :email)
+    grabbed = grabbed ? "#{grabbed}%" : email_address
+    user = where("email LIKE :email", email: grabbed).first_or_create do |u|
       u.name= auth.info.name
       u.email= auth.info.email
     end
diff --git a/db/schema.rb b/db/schema.rb
index 0f6aaf0..022b094 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -51,7 +51,7 @@
     t.string   "token"
     t.string   "profile_picture"
     t.string   "profile_url"
-    t.string   "profile_email"
+    t.string   "email"
   end
 
   add_index "social_providers", ["user_id"], name: "index_social_providers_on_user_id"