fixes #1479

app/models/tag.rb

@@ -561,6 +561,10 @@ class Tag < ActiveRecord::Base
     end
   end
 
+  def editable_by?(user)
+    user.is_builder? || (user.is_member? && post_count <= 50)
+  end
+
   include ApiMethods
   include CountMethods
   extend ViewCountMethods