ActAsParanoid para Rails 3

acts_as_paranoid.rb

module ActsAsParanoid

  def acts_as_paranoid
    default_scope where(:deleted_at => nil)
    include InstanceMethods
  end

  module InstanceMethods

    def destroy
      run_callbacks(:destroy) do
        if persisted?
          self.update_attribute(:deleted_at, Time.now.utc)
        end
        @destroyed = true
        freeze
      end
    end
    
  end

end

ActiveRecord::Base.extend ActsAsParanoid