Getting people to enter lots of information into your service with no awareness of a future in which each edit, rather than just the end profile, will be revealed, and then launching a feature that reveals each little edit the person has ever made.
Similar to pulling the rug out from under your software's users, or violating expectations you've created.
"Don't take all of his myspace photos and put them on the homepage. That's like pulling a facebook."
Ruining your product trying to catch up with a quickly rising competitor, constant updates that don't actually improve anything, risking integrity and original goals out of fear of becoming obsolete
Man, Mozilla is really pulling a facebook with all the useless updates since Firefox 4.
Yeah, they're only making it easier for Google to swoop up all of their users with Chrome