Social networking sites are now rampant with viruses and spam, according to the New York Times. For Viral Crooks, Social Networks are Prime Targets, is an important read for everyone who uses social networking sites such as Facebook and Twitter.

Here are some scary statistics excerpted from that article:

Sophos says that 21 percent of Web users report that they have been a target of malicious programs on social networks. Kaspersky Labs, a Russian security firm, says that on some days, one in 500 links on Twitter point to bad sites that can infect an inadequately protected computer with typical viruses that jam hard drives. Kaspersky says many more links are purely spam, frequently leading to dating sites that pay referral fees for traffic.

The problem lies in the fact that people are much more likely to trust a link they think was sent to them by a friend.

Twitter sites can now be hijacked so that before you know it you’re broadcasting someone else’s message to your contacts.

Bottom line? Think before you click. Ask your contact if you’re not sure. And check your social networking accounts frequently to make sure you’re not inadvertently sending out the wrong kind of message!