The popular social networking site MySpace is beginning to have problems with spam, phishing, porn, and other kinds of unfriendly and malicious content. At the root of much of this is the anonymity of the sites. Anyone can register as a MySpace user, which has delighted sexual predators who use the site to find vulnerable underage children.
The phishing schemes are made simpler because you don't ever really know who you are talking to in a MySpace group or content area. So "someone" who appears to be interested in the same things you are might turn out to be a credit card crook from Asia. The business of spam and Internet fraud is accelerating as more and more parts of the world get connected. Go to a small, poor Asian country, and you can hire people for a $1 an hour to place spam on Web sites with discussion forums (which is why I had to disable anonymous posting on this site).
Eventually, we will evolve solutions to minimize many of these problems, but others may be with us for a long time.