In 2015, ESPN reported that the New England Patriots had long had a reputation in the NFL for cheating.
A former member of the NFL competition committee told ESPN that from 2001-2006, the committee spent much time "discussing ways in which the Patriots cheated."
Source: ESPN
Bill Belichick, who runs the Patriots' football operations, has often been considered the mastermind of the schemes. A former Patriots assistant coach told ESPN that Belichick would be good at doing taxes because he'd find "loopholes."
Source: ESPN
The biggest cheating scandal was "Spygate," in which the Patriots filmed opponents' offensive and defensive play signals to study them. The Patriots would recognize signs during the games and relay them through headsets.
According to ESPN, the videographers filming the signals would go to games as employees of Robert Kraft or Patriots TV and had excuses for what they were shooting, such as a team show.
Source: ESPN
Though the Patriots had long been accused of filming opponents' signals, the scheme truly came to the surface when the New York Jets caught them in the act. Then-Jets head coach Eric Mangini, a former Patriots coach, knew of the scheme and told security to be on alert.
The NFL investigated the Patriots, eventually destroying tapes the Patriots had of opponents' signals. The Patriots were docked a first-round pick and fined $250,000. Belichick was fined $500,000. He later said he misinterpreted the rules.
The next biggest scandal was "Deflategate," in which the Patriots were accused of deflating footballs before the 2014 AFC Championship.
The Indianapolis Colts discovered the Patriots balls were below the legal PSI limit. The scandal included damning texts between Patriots employees about handling the balls, Tom Brady destroying his cell phone before handing it to NFL investigators, and a seemingly never-ending court battle.
It eventually ended with Brady serving a four-game suspension, the Patriots being fined $1 million, and losing a first- and fourth-round draft pick.
According to ESPN, there has been league-wide "paranoia" about how the Patriots would cheat.
Source: ESPN
According to ESPN, former Patriots staffers would admit to some methods of cheating during the Spygate years. For instance, they would steal play sheets from the opponents' locker room.
The practice became so widely known that opponents started putting fake play sheets out.
Source: ESPN
Opponents also said their headsets would get scrambled when they played at Gillette Stadium.
One of the more recent accusations came from Steelers head coach Mike Tomlin, who said in 2015, the Steelers headsets were tuned to a local radio station. According to NFL rules, when one team's headsets fail, the other team is supposed to abandon using theirs. Just as the Patriots were going to be told to stop using theirs, the Steelers headsets began working again.
"That's always the case [at Gillette Stadium]", Tomlin said.
Some opponents were worried that the Patriots bugged their locker rooms. Peyton Manning famously would only speak to coaches outside the locker room.
There were "regular rumors" that the Patriots filmed the Rams walk-through for the 2001 Super Bowl, which the Patriots won in an upset.
Source: ESPN
The Eagles were paranoid of the same thing. They ran a fake walk-through prior to the 2017 Super Bowl in case the Patriots were filming it.
Occasionally, odd things have happened to Patriots opponents before big games. In 2017, the Steelers had to evacuate their Boston hotel after someone pulled the fire alarm at 3 AM on the day of a game against the Patriots.
The man who did it had no connection to the Patriots, but the incident still raised eyebrows.
The Patriots have drawn criticism for finding gray areas in the rules. In 2015, they ran a brilliant trick play vs. the Ravens in the playoffs that upset John Harbaugh.
The Patriots lined up an ineligible receiver in the slot and an eligible receiver where an offensive lineman would normally be. The play baffled the Ravens, who felt the Patriots weren't making clear who was eligible and ineligible (as are NFL rules). Harbaugh said the play was "deception." The NFL later banned the formation.
