in most cases, yes. nobody gets cyberbullied on websites where you're anonymous, whether it be by the huge amount of users (think youtube) or by design (think 4chan). when you get into more personal websites like facebook, i think it can be harder to get away from.
unless you post personal information or are totally dependent on the forums for social interaction, i think you could walk away from the BLF pretty easy if you think you're being bullied. the issue for a lot of users is that they're really attached to this forum and they don't want to leave, even if it's the better decision. i can think of a few users who would be much happier (and much better liked) if they had left while they were ahead.