The windows near the elevators on the 21st floor of the Sheraton Meadowlands Hotel in East Rutherford, N.J., are fit for football espionage. The Giants' practice field sits about a mile in the distance, past the maze of highway lanes and off-ramps, past the massive parking lots.

If a coach stands on that field and looks back at the hotel, all sorts of paranoid possibilities come to mind. Visions of men in disguises renting rooms, setting up telescopes and video cameras, and gleaning valuable information from the opposition. Legend has it that over the years Giants coaches have sent security personnel to the hotel to conduct sweeps. They never reported finding anything or anyone.

Coaches in the NFL may rank among the most paranoid people on the planet, along with counterintelligence agents and UFO conspiracy theorists. They shred game plans. They sweep offices for bugs. They surround team headquarters with security. They close practice. They refuse to talk about injuries. Some teams, like the Jets, have paper shredders in their locker rooms.

The paranoia runs so deep sometimes that one must wonder if coaches in the NFL have forgotten that the talent on the field, not the security detail surrounding it, typically determines who wins.

"Ever since there have been coaches, there has been paranoia," said Randy Cross, a TV analyst who played for the 49ers. "When the first coach invented the wheel, he guarded it from other coaches. That's part of the culture. You have to go to spy agencies, the United Nations, to find parallels."

After Jets linebacker Jonathan Vilma sustained a knee injury this season, coach Eric Mangini was asked at a news conference if he knew which play the injury occurred on. He said no.

Q: Do you know which knee?

A: Yes.

Q: Are you going to tell us?

A: No.

Q: Right or left?

A: Tricky. It's one of those two.

The injury occurred Oct. 21. On Monday, Mangini finally identified which leg was hurt — the right one.

Players are charged thousands of dollars for losing playbooks, and game plans, which include more specific plays and strategy, are worth their weight in gold. Teams commonly sign players who were cut the week before by their next opponent.

Coaches usually refuse to discuss injuries, and they make a mockery of the league's official injury reports. Bill Belichick, coach of the New England Patriots, often lists more players than are actually injured as questionable for the next game. Several teams close practices to the news media, and those that allow reporters to watch usually ask them not to report about strategy.

"The most glaring reminder came when I was watching 'Monday Night Football' the other night," Cross said. "Brian Billick kept covering his face with his play card — I guess they are covering up the quote-unquote world-class secrets everybody has," he added, referring to the Baltimore Ravens' coach.

Football paranoia predates game plans, computers, technological innovations and around-the-clock television coverage. Historians credit Gallaudet University, a university for the deaf, with inventing the huddle in the 1890s to prevent opponents from reading sign language. Now, coaches cover their mouths, in case opponents employ lip readers to watch telecasts.

George Allen, a former Washington Redskins coach, hired a retired police officer to search for spies and sent him hunting through the bushes around the team's facility.

"I don't know if paranoid is the right word," said Charley Casserly, a former NFL executive who worked for Allen. "He was protective and cautious, suspicious of people."

Did he ever find something in the bushes? "Not that I know of," Casserly said. "I don't know if anyone ever finds anything there."

Paranoia means someone is characterized by extreme suspiciousness, grandiose delusions or delusions of persecution. Consider George Seifert, who won two Super Bowls with the San Francisco 49ers: When a jogger stopped to tie his shoe on the bridge next to the team's practice field, Seifert sent security over. He later attempted to ban helicopters from flying over the field.

Walt Michaels was coaching the Jets when they beat Al Davis' Raiders, in Los Angeles, in a playoff game in 1983. But instead of exulting afterward, Michaels ranted about a phone call he received at halftime from a Queens bartender impersonating the Jets' owner, Leon Hess. Michaels was convinced Davis had orchestrated the call.

Deep suspicion is not entirely unfounded. Last month a network television camera zoomed in on Seattle Seahawks coach Mike Holmgren, revealing his play card. Two months ago, a Patriots employee was found to have stood on the sideline with a hand-held camera, recording the defensive signals used by Jets coaches, a violation of NFL rules. Belichick was fined $500,000, and the Patriots were fined $250,000 and stripped of at least one draft pick.

Teams have long suspected bugs or cameras hidden in locker rooms or in meeting rooms during contract negotiations. Some teams hire security to sweep rooms and ensure secure connections. Casserly said some teams put wires on defensive linemen, recorded signals and matched the audio to game tapes.

"There has to be a point of diminishing returns," Cross said. "The more time you spend away from the ball, the less time you spend actually preparing."

Brian Tuohy wrote an article for Paranoia magazine titled "The NFL: Professional Fantasy Football?" which explored conspiracy theories in the league.

"Paranoia exists to some degree," he said. "Most coaches are secretive, manipulative, controlling. I just don't know how much they have to be paranoid about."

Murray Associates, a New Jersey company that provides eavesdropping protection, has been hired by several professional sports teams to ensure secure contract negotiations, said the company's president, Kevin Murray. Three of the teams that hired Murray were NFL teams — all within the past five years.

Murray said he believed espionage in sports was more prolific now, with so much money and fame at stake. And bugging an office "is easier now than at any time in history." For example, Murray said, someone could stick a prepaid cell phone on the ceiling of an office, turn the ringer off and set the phone to auto-answer. Then that someone could listen from anywhere in the world.

"Some people sound on the paranoid side, but they're really just normal people, following their instincts," Murray said. "And usually, they're correct. Coaches would be silly not to be checking."

So coaches will continue look for spies behind trees, in bushes, behind the wheel of the team bus. If you are not paranoid, they say, you are not paying attention.

The view from the Sheraton Meadowlands Hotel demonstrates how spying is possible, if not far-fetched. And for NFL coaches, that is enough.