REP. BARNEY FRANK, D-Mass., says that "some adults will spend their money foolishly, but it's not the purpose of the federal government to prevent them from legally doing it." Especially when the government can tax that foolishness.

Before Congress left on its summer break, the House Financial Services Committee, which Mr. Frank chairs, passed a bill that would legalize online gambling, including poker and sports betting. All that remains to slap a smile on Mr. Frank's face is for a companion bill--the one that would establish the taxes--to make its way through committee.

Proponents are betting that legalizing online gambling and letting the IRS take a cut could put as much as $42 billion in Uncle Sam's coffers over a decade--easily enough to stimulate the prey impulse in revenue-hungry congressmen. But it doesn't take into account the bigger lion waiting in the bushes: the human costs of gambling.

Taking into account increased crime, lost work time, bankruptcies, and various financial hardships, gambling costs the economy as much as $54 billion annually, writes Earl L. Grinols, an Illinois economist, in "Gambling in America: Costs and Benefits." Every problem gambler, according to R. Keith Schwer et al., costs society an average of $19,085 per year.

We already know from other studies that proximity to a gambling facility increases the percentage of problem gamblers in a population. Legalizing Internet gambling would put a casino in every home, and, indeed, one in every hand that holds a smart phone.

In fact, says Rep. Spencer Bachus, R-Ala., Internet gambling is different: "Online players can gamble 24 hours a day from home. Children may play without sufficient age verification. Betting with a credit card can undercut a player's perception of the value of cash, leading to addiction, bankruptcy, and crime." Furthermore, says Mr. Bachus, "when you put a computer in the bedroom or dorm room of a young person, the temptation is too great for many of them to resist."

A study by Robert B. Breen of Brown University found that the development of pathological gambling occurred much faster with "machine" gambling, compared to more traditional, face-to-face forms. "We suggest that gambling machines 'deliver' their 'active ingredient' more rapidly, continuously, and directly than the traditional forms of gambling," he wrote. Perhaps that's why John Kindt, a professor of business administration at the University of Illinois, calls Internet gambling "the crack cocaine" of betting.

"People sometimes resort to drastic things when they are strapped for cash," said Rep. Robert W. Goodlatte, R-Staunton. His word for Mr. Frank's proposal? "Unfathomable."

Fortunately (on a lot of fronts) Congress is taking a seven-week vacation and won't have much time to pursue legalizing Internet gambling before the November elections. So the chances of Mr. Frank succeeding at his ill-advised wager? We'd say 300-to-1. If we're lucky.