Ars Technica talks about dark patterns:
Everyone has been there. So in 2010, London-based UX designer Harry Brignull decided he’d document it. Brignull’s website, darkpatterns.org, offers plenty of examples of deliberately confusing or deceptive user interfaces. These dark patterns trick unsuspecting users into a gamut of actions: setting up recurring payments, purchasing items surreptitiously added to a shopping cart, or spamming all contacts through prechecked forms on Facebook games.
I can’t recall ever falling for a dark pattern, but I see these things everywhere – a sure sign that whatever company, website, or whatever, you’re dealing with is not worthy of your time.