Hooliganism, once a rampant problem in England, is threatening to undermine soccer in Argentina, says SI.com’s Gregory Saha, who says that Argentine gangs have never had so much influence over the sport. “Futbol,” he says, “has taken a back seat to violence and corruption” — which is a shame, because the Argentine league has the most passionate fans in Latin America, if not the world. The rivalry between River Plate and Boca Juniors, one of the most famous in the world, is consistently described as a spectacle unmatched in any sport.

However, Saha says that recently, the obsession these loyal fans have with their clubs “has manifested itself into massive-scale crowd violence during and after games, and has often ended in deaths.” Which means that attending matches is no longer safe for the neutral supporter. “The most troubling part,” Saha says, “is that the soccer authorities — and even the Argentine government — have been unable to find a solution.

Who are these gangs? They’re actually professional organizations of between 100 and 300 members that deal with lots of money. One that supports River is Los Borrachos del Tablon; another called La Doce supports Boca and is believed to have more than 2,000 members. The leader of the latter group was imprisoned in March. A member of Los Borrachos was gunned down by someone in his own organization. And who supports these gangs? Argentina’s main national newspaper, Clarin, alleged that “not only do club directors and players fund the barra bravas, but so do celebrities and politicians.”