New US law have not stopped internet gambling. Offshore sites simply set up shop where US law enforcers can't reach them, and domestic gamblers are finding alternative ways to pay.

When the US Congress specifically criminalised internet gambling at the end of September by outlawing credit-card payments to the services, it failed to stop aspiring card sharks and sports fans from parting with their wages, experts say.

People who bet online will not face criminal prosecution under the law because it does not ban internet gambling; instead it requires that banks and other financial institutions block credit-card payments to gambling sites.

"If you send a cheque in, you'll be fine. There's no way it's going to stop," said Frank Catania, a former New Jersey gambling regulator who currently lobbies for the online-gambling industry. The Federal Reserve is not expected to force banks to screen personal cheques or other payment methods that are more difficult to track, experts say.

Internet gambling is booming. By last summer, US gamblers accounted for half of the industry's $12 billion (£6.17bn) in revenue, and online gambling stocks of the likes of PartyGaming were flying high on the London Stock Exchange.

In the wake of the law's passage, investors in London sold off PartyGaming and other Internet gambling stocks, erasing $7bn from the stock exchange in a matter of days. Many of those British companies said they would no longer accept wagers from their most lucrative market across the Atlantic.

But other gambling sites, such as the privately owned Bodog and PokerStars, say they will continue to serve American customers. Their Caribbean locales put them beyond the reach of US law enforcement – unlike gambling executives in Britain, who face extradition to this country under a 2004 treaty originally intended for extraditing terror suspects.

Industry pundits don't expect the ban to end online gambling. "I have no doubt the private operators will pick up the slack," says Tejinder Randhawa, an analyst for Evolution Securities in London.

Congress could still decide to roll back or modify the law. The Poker Players Alliance hopes to mobilise the 23 million online card players in this country into a powerful lobby to counteract opposition to online gambling. "Prohibition doesn't work," says Alliance president Michael Bolcerek. "[Congress] should have offered legislation that places a high priority on making sure that kids don't play poker online, and address [gambling] addiction." Instead, Bolcerek says, "you'll find sites that won't abide by industry aims to safeguard the American public."

For now, online gamblers are cautiously making other plans. Lee Sullivan, of Alexandria, Virginia, says she might spend less time in front of the computer and more time at the corner bar shooting pool.

"If it all goes away, it'll be a bummer – but it won't be the end of the world," said Sullivan, who won a free trip to last August's World Series of Poker after qualifying through the PokerStars site. "Still, I don't see how the US government can put the toothpaste back in the tube on this one."