Sport: Football.
Why they're bad to the bone: They're unapologetically successful, and that alone is enough to make anyone who isn't a New England Patriots fan loathe them.
Together, Patriots coach Belichick and quarterback Brady have won six Super Bowl championships and are the key reasons for the New England dynasty in the NFL.
But the apparent means used to get that success has come under scrutiny, with the Los Angeles Times earlier this year calling the Patriots "football's perfect villain — cheating, haughty, hated."
Under Belichick's watch, the Patriots were caught videotaping opponents' defensive signals in 2007. This became known as "Spygate."
And if that were not bad enough, there was then "Deflategate," when the league believed Brady probably knew deflated footballs were going to be used in the 2015 AFC Championship Game against the Indianapolis Colts, something that would have given the Pats an advantage during offensive plays.
The whole ordeal inspired a 10-year-old called Ace Davis to create an entire science project about it, as he hoped to conclude that Brady is a cheater.
Read more: A 10-year-old boy won a science fair with a project concluding that Tom Brady is a cheater