Sneaky user interfaces, such as unwanted bundleware default checkboxes [theguardian.com] are now expanding into digital newspaper subscriptions [rationalconspiracy.com]. The Boston Globe's site uses lightly-colored close buttons and increases the price as the user goes through the sales process, as well as includes some newsletter-signup defaults. These dishonest-by-design interface elements that are intended to trick or obfuscate users are called dark patterns [darkpatterns.org].
What are some of the most egregious examples you have seen? Have you even been asked to implement a design you found morally distasteful?