[smsm42]

There are two general reasons not to trust Facebook:

1. The reason not to trust {big company X} is that there's no reason to trust them. Their interests are not your interests. They are big enough that loss of one client is nothing for them. They have more lawyers than you have dollars, so short of overt crimes they would be able to do anything with your data and you could do nothing to them. They are popular enough that if they don't screw up something major they can live with significant number individuals pissed off about them and not care the least.

2. Facebook management's position, which they expressed a number of times publicly, is that anonymity is harmful and privacy has no value and should not exist on the internet. Here's but one example: http://www.readwriteweb.com/archives/facebooks_zuckerberg_sa... If I had to choose one company that should not be trusted with my private info that would be the one whose founder publicly states that privacy should not exist. In short, consider any info going into Facebook as if it were to be published in New York Times. If you're not OK with that - keep it to yourself.