Just like most of the internet. Once you put it out there anyone can find it and it's out there for the world to see. They talk about Facebook all the time, but wouldn't this classify as basically the same thing, a social network? Just be careful what you put out there, or it could come back to bite you in the butt. Follow this general rule: If you think it will come back to bite you, don't put it out there to begin with. Pretty simple actually.