The only sounds in the stadium are the referees' whistles and the constant thump of foot meeting ball.

No throaty screams, no blaring horns, no cheers, no boos.

This is what happens when European soccer fans go bad: Their favorite teams are sentenced to play future games in an empty stadium. Then the leagues get strict. Unruly rooters who unleash racist remarks at players can be banned from a stadium for two years, and fans who rush the field face six months in jail.

Massive tragedies, including the stampede death of nearly 100 British soccer fans in 1989, have fueled a wave of vacant stadiums and iron barriers across Europe. In Turkey, France and Italy, soccer fans are separated from each other and the players by fences or Plexiglas walls that often eat up seating space. The common thread in the crackdown: European soccer officials are willing to sacrifice game-day revenue to bump up safety.

As the beer dries and the bruises heal following the Nov. 19 melee at a Detroit Pistons game, some American sports observers say it's time for tough love on home soil. But a few also wonder if U.S. owners and league honchos are willing to lose money in order to keep the peace.

"You've got to care about this stuff and you've got to be willing to say safer arenas matter more than a little profit," says Joseph Kinney, a stadium security expert. Kinney helps pro and college teams control their crowds, teaching the importance of plucking out troublemakers.

Indeed, some of the game-day crackdowns in place globally have become common tactics at American sporting events. Cops in riot gear have been stationed at soccer games in Italy and Portugal when brawls were expected. Well-armed U.S. police ring college football fields in the final seconds of big games, aiming to scare off any fan intending to rip down the goal posts.

But can you imagine tuning in to watch Chauncey Billups and the Pistons fire up 3-pointers in an arena devoid of fans, vendors or energy? Just this fall, soccer clubs in The Hague and Rome each were ordered by their leagues to play against a back drop of unfilled seats after spectators had chanted nasty slogans and pelted officials with coins.

Still, simply clearing a stadium - or banning bad fans for up to two years - aren't enough to quell future uprisings, says Nicolas Maingot, a spokesman for FIFA, the international governing body for soccer. As penalties are meted out, sports officials must also talk directly to the fans and players, remind them that it's all just a game.

"Whenever there are incidents, there must be sanctions, and that's clear for everybody," Maingot says. "But with sanctions, we always appeal for the fans, for the players to show greater attitude. Sanctions alone are not enough."

Forcing American teams to play games without their fans has support among some U.S. stadium security experts.

"That would not bother me," says Kinney, whose clients include the Carolina Panthers. "This is an important issue. We don't need more violence, we need less. We talk about zero tolerance for drugs. I've seen as much damage from violence in this society as I have seen from drugs."