MONTREAL - For hotel, restaurant and bar owners, the Grand Prix is what Christmas is to retailers, as tens of thousands of well-heeled jet setters slap down their gold cards without any mind for the bottom line. 

For one glorious weekend, caviar, Grey Goose and luxury suites are all in high demand, leading to a luxury market markup for many Montreal business owners.

However, the threat of disruption from disgruntled tuition protesters has parked a dark cloud over the upcoming weekend.

"It's one of the biggest weeks of the year and it could become the worst weeks of the year," said Crescent Street restaurant owner Peter Bakopanos.

A group known as Anonymous has already hacked and published the name of 131 Grand Prix ticket purchasers.

A group called the Anti-Capitalist League has vowed to crash the event's cocktail party.

The most radical of the three main student groups had offered some implicit support for the subversive tactics by refusing to denounce them.

But on Friday the CLASSE appeared to distance itself from participating in any disruptions, vowing instead simply to try to peddle pamphlets to the tourists.

"We will probably be there to distribute some information to the people," said CLASSE representative Gabriel Nadeau-Dubois.

But after the breakdown in the tuition talks, the CLASSE leader didn't want to downplay the possibility of some expression of outrage.

"You have to understand we cannot block the hundreds of thousands of students of Quebec from doing an action if they want to do an action," Nadeau-Dubois told CTV Montreal. 

Any loss will cost the government as well as the merchants, as one businessman pointed out.

"It's a lot of money for the city the government taxes, GST, PST," said Ralph Toteda.

Mayor Gerald Tremblay seemed preoccupied by possibility that Montreal might look like a bad host.

"We're concerned. We've had different meetings with the business community and we've got to make sure that we find a solution," said Mayor Gerald Tremblay.