Caroline Dangson, an analyst with IDC, noted that spam is a problem especially for Facebook, which appeals to people looking to develop a private network where people need permission to send them messages.

"These consumer applications are free to use. Too much spam will push people away," she said. "We've seen Twitter recently add features to make it easier for users to report spam, most of which is pornographic."

Rob Enderle, an analyst with the Enderle Group, said that dealing with spam should be a top priority of social networks.

"Spam is a massive resource problem in a world that is already network constrained," he said. "It reduces the value of everything it touches and is a substantial drag on national productivity. Inside or outside of social networks, it should be a top priority."

Ezra Gottheil, an analyst at Technology Business Research, said if spam gets out of control, usrs may abandon what are now their favorite social networks.