A while ago I connected to openstudy.com using my Facebook settings. Due to lack of time I decided to leave this initiative by deleting it from Facebook. Although it is a very nice initiative (mit opencourseware, nyu, etc… are participating) I found that deleting it from Facebook does not seem to kill your account there. You need to login again using Facebook and then disable the notifications. This is one thing but there is another problem.
Once logged in again there is no clear way to cancel your account. This is a bad thing imho…..