CHEYENNE - One or two of every six Americans can be considered a criminal.

That is the estimated number of people in this country who illegally wager money each year on sports.

The racket reaches its height during football season.

Various estimates place the number of Americans who bet on sports each year at 50 million to more than 100 million, and the lion's share of them do it illegally.

They can do over the Internet or by telephone, with Nevada sports books, with off-shore companies, or with people across the country who act illegally as bookies.

However it's done, it's a big business.

In 1999, the National Gambling Impact Study Commission found that illegal sports betting nationwide totaled $80 billion to $380 billion a year.

The most popular sport for gamblers is pro football, and some say that's part of the reason the National Football League has become the country's most watched and most successful professional sports league.

People bet more than $5 billion each year on the Super Bowl alone. That's more than the gross domestic product of Mongolia.

Some of those wagers include handshake bets with friends, betting with bookies, or buying a square in a pool at virtually any bar with the payouts determined by the score of the game.

Authorities are aware of this popular and widespread criminal activity, but they rarely do anything to stop it. Part of that is because it's so hard to prosecute, and it's hard to tell in many cases when a bet is or isn't illegal, according to Wyoming Attorney General Pat Crank.

Wyoming law generally prohibits gambling, but the state's definition of "gambling" does not include any bet that is "incidental to a bona fide social relationship."

That means a handshake bet between two friends on the outcome of a football game does not appear to violate state law, Crank said.

But other situations are not so clear-cut.

Internet betting is a booming industry that the American Gaming Association estimates at over $5 billion per year today. That amount is expected to triple within the next five years.

What if someone has an online betting account with a casino in Nevada or another country? No money changes hands in Wyoming, so to speak, but the person placing the bets is doing it from a computer in Wyoming.

"That's a really hard question. As a former prosecutor, it would occur to me that would be a really hard violation to prosecute," Crank said. "My opinion is, if you're doing it from Wyoming it may very well violate Wyoming statutes, but that would be an incredibly difficult case to investigate or prove or prosecute."

A football pool in which all the money paid in by the bettors gets paid out to the winner or winners is probably not illegal in Wyoming, Crank said, unless the bar or whoever is hosting the pool takes a share of the money wagered.

"All these things are open questions," he said, and every scenario presents a unique set of facts a prosecutor would have to analyze before reaching a conclusion about its legality.

But before that could even happen, someone would first have to bring the matter to the attention of authorities.

Then again, sports gambling is so common and widespread that it has, to some extent, become ingrained into the nation's culture.

Every week, newspapers across the nation - including this one - publish point spreads for the games.

Many mainstream sports columnists offer their predictions of upcoming games, down to the final score, and they keep running tallies of their success, both "straight up" and "against the spread."

While some people may claim to come out ahead betting on sports, the odds are against them.

Bookies set, and then adjust, the point spreads in order to entice gamblers to bet the same amount of money on each team, and bookies also get a share of the money bet.

As ESPN.com's Bill Simmons warned readers in his gambling column last week, "There's a reason Vegas keeps building casinos; there's a reason you never hear about a bookie declaring bankruptcy; and there's a reason you usually don't hear waitresses in West Hollywood bragging about how much money they're winning on football. Just remember, they call it gambling for a reason."

Capital bureau reporter Bill Luckett can be reached at (307) 632-1244 or at bill.luckett@casperstartribune.net.