Find old friends and make new ones. Social networking sites like Facebook and MySpace are a great way to stay in touch, but they're also a great way for spammers to annoy users, it turns out. More than 100 million people now have MySpace accounts. One-hundred thirty-two million unique visitors went to the Facebook home page in June. That's a lot of potential targets, and spammers are signing on. A recent survey found 83 percent of social network users had received spam in the last year, most innocuous "friend" requests that turn out to be marketing. Some of the requests were more adult in nature. For example, some reported invitations to join pornographic Web sites. Larry Rosen is the author of "Me, MySpace and I." He said that's common. "Some of those are from businesses that want you to be their friend because they're looking for business, some are from porn stars who set up their MySpace page," he explained. "What it often does is clogs up your computer." That's turning some people off to online networking. "I did end up canceling my account," said Scott Mariano. Helen Carabez doesn't like it, but isn't quitting MySpace. "I consider it annoying but I just ignore it, I just delete it,” Carabez said. The easiest solution: Turn up the privacy settings to block messages and friend requests. The real concern comes with children, who love the idea of collecting friends. Friends... who are actually strangers. Larry Rosen said you need to talk to kids about what they may encounter when networking. "Ask them, well, what would you do if you get an email that's not very nice, how will you handle it?” Rosen said. Joy Dudley's kids network, and she keeps a close eye on what they're doing online. "I always have told them to be careful who you communicate with when you're online," Dudley said. MySpace uses special technology called "captcha" to stop mass emails sent out over their site. Facebook told us they do not tolerate spam and also monitor for repeated messages sent to groups.