Why do you need to protect yourself from trolls on facebook? Those are your friends. Unless you add every stranger that send you a friend request.
I'm not in favor of Germany on this one but sometimes the law/government should interfere to ensure people freedom. Just because it's a private company doesn't mean they can do whatever they want with our data even if we were the ones providing the data.
I use FB mainly for information distribution and conversation. It means that I interact with friends of friends, and with people who "are going" to my event (and I'm not knowing them in person). (And yes, I add Internet-only acquaintances, but not guys I don't know.)
Some of my personal experience says that (usually, not always) people under names don't troll that much.
Of course, the situation is different for small communities, or skill-driven communities, but (usually) not for open ones. (E.g. on HN anonymity works well.)
I don't say that I agree with FB's rules (personally I prefer "real names encouraged, but not required" policy on such "for everyone" sites). I'm just saying that there are pros and cons, both for FB and for its users.
I'm not in favor of Germany on this one but sometimes the law/government should interfere to ensure people freedom. Just because it's a private company doesn't mean they can do whatever they want with our data even if we were the ones providing the data.