I wrote earlier about P2P Betting Looking Better. It's gone from better to best with the U.S. Congress outlawing Internet gambling.

A last minute rider ramrodded by Senate Majority Leader Bill Frist snuck it into a port security bill. The law outlaws Internet gambling, which already was illegal, by outlawing the use of banks to pay for it. The law is ineffectual in many ways and easily circumvented. It amounts to political grandstanding. For more on that I recommend Robert X. Cringely's article "Risky Business: Congress stupidly outlawed Internet gambling and only terrorists were helped."

Even if there was a way to reasonably and accurately track, contain, and litigate gambling payments, it couldn't cover decentralized P2P gambling where betters bet against one another.