“Hidden costs are now illegal, whether that’s an undeclared subscription, extra shipping charges, or extra items. While the costs are still permissible, failing to advise the customer about them or explain what they are is not. Everything has to be brought out in the open, explained, and clarified before checkout.”

http://www.90percentofeverything.com/2014/08/26/some-dark-patterns-now-illegal-in-uk-interview-with-heather-burns/