Approximately 15% of Twitter traffic, 10% of MySpace traffic and 7% of Facebook traffic is porn spam

"About 15% of Twitter traffic, 10% of MySpace traffic and 7% of Facebook traffic is porn spam, according to security expert Alexandru Catalin Cosoi of BitDefender.
What's more, as porn spam rises on social sites, email-based porn spam has begun to drop.
Twitter, presently the "it" brand of social networks, currently suffers from a deluge of spam. Spammers register as users with provocative images, then follow mounds of other users and invite them to visit links to their sites."
Source: Research by BitDefender, reported by MarketingVox, 11th September 2009