I had an HTC Droid Incredible. Facebook was included in the factory build, was always running per the process list even after force quitting, and with the exception of rooting the phone [0], was impossible to remove from the device.

http://forums.androidcentral.com/verizon-droid-incredible/10...

[0] Corporate-provided and payed-for phone, so I was prevented from rooting because of "security reasons." Even after (or, especially because) the phone developed the surprising habit of snapping pictures at random times -- as evidenced by the distinct sound made by my DInc's shutter -- after the corporate-required malware was installed. I'm sure someone, somewhere really enjoyed the view of the inside of my pocket.