There was an article in the The Register earlier this week titled Twitter
fanatic glimpses dark side of OAuth which contains the following excerpt

A mobile enthusiast and professional internet strategist got a glimpse of OAuth's
dark side recently when he received an urgent advisory from Twitter.  The dispatch,
generated when Terence Eden tried to log in, said his Twitter account may have been
compromised and advised he change his password. After making sure the alert was legitimate,
he complied.

That should have been the end of it, but it wasn't. It turns out Eden used OAuth
to seamlessly pass content between third-party websites and Twitter, and even after
he had changed his Twitter password, OAuth continued to allow those websites access
to his account.


…


Eden alternately describes this as a "gaping
security hole" and a "usability issue which has strong security
implications." Whatever the case, the responsibility seems to lie with Twitter.

If the service is concerned enough to advise a user to change his password, you'd
think it would take the ad