CAMPINAS, Brazil — On the night of March 8, cruising 22,000 miles above the Earth, U.S. Navy communications satellite FLTSAT-8 suddenly erupted with illicit activity. Jubilant voices and anthems crowded the channel on a junkyard's worth of homemade gear from across vast and silent stretches of the Amazon: Ronaldo, a Brazilian soccer idol, had just scored his first goal with the Corinthians.

It was a party that won't soon be forgotten. Ten days later, Brazilian Federal Police swooped in on 39 suspects in six states in the largest crackdown to date on a growing problem here: illegal hijacking of U.S. military satellite transponders.

"This had been happening for more than five years," says Celso Campos, of the Brazilian Federal Police. "Since the communication channel was open, not encrypted, lots of people used it to talk to each other."

The practice is so entrenched, and the knowledge and tools so widely available, few believe the campaign to stamp it out will be quick or easy.

Much of this country's population lives in remote areas beyond the reach of cellphone coverage, making American satellites an ideal, if illegal, communications option. The problem goes back more than a decade, to the mid-1990s, when Brazilian radio technicians discovered they could jump on the UHF frequencies dedicated to satellites in the Navy's Fleet Satellite Communication system, or FLTSATCOM. They've been at it ever since.

Truck drivers love the birds because they provide better range and sound than ham radios. Rogue loggers in the Amazon use the satellites to transmit coded warnings when authorities threaten to close in. Drug dealers and organized criminal factions use them to coordinate operations.

Today, the satellites, which pirates called "Bolinha" or "little ball," are a national phenomenon.

"It's impossible not to find equipment like this when we catch an organized crime gang," says a police officer involved in last month's action.

The crackdown, called "Operation Satellite," was Brazil's first large-scale enforcement against the problem. Police followed coordinates provided by the U.S. Department of Defense and confirmed by Anatel, Brazil's FCC. Among those charged were university professors, electricians, truckers and farmers, the police say. The suspects face up to four years and jail, but are more likely to be fined if convicted.