While Web users drown in spam and fend off scams aimed at stealing their money, U.S. federal and state law enforcement authorities are doing little to resolve what has become a multi-billion-dollar problem, a think tank said. In the 20 states that give a number for consumer complaints, there were roughly 20,000 Internet-related complaints in 2007, said the group, which surveyed officials in all 50 states but received widely varying amounts of data.