The NFL has a reputation for being a little overzealous in levying fines against its players and coaches. The league fined Chicago Bears wide receiver Brandon Marshall $5250 for wearing green shoes during a game a couple of weeks ago to recognize Mental Health Awareness Week (according to league rules, all uniform changes have to be pre-cleared). And Detroit Lions defensive tackle Ndamukong Suh is paying a record $100,000 fine for an illegal block.

But just where does that money go?

According to the NFL, all money collected from fines goes to charitable causes, including supporting its retired players. In a 2010 statement, the NFL responded to public comments from Pittsburgh Steelers safety Ryan Clark, who publicly challenged the NFL to give back fine money in the event of a player lockout. They clarified that all on-field fines go to the NFL Player Care Foundation—which provides medical, emotional, and financial assistance to retired NFL players—and the NFL Players Association Player Assistance Trust, a fund that helps professional and amateur football players' families in a crisis. The money can also go to various disaster relief and health-related charities backed by the NFL.

In a 2011 interview with the AP, NFL director of community affairs David Krichavsky said that some players will even request what charity their money goes to, but said that the league will "stay universal" in distributing the money.

As for Marshall's fine, he said that not only was he happy to pay it, he'd even match the funds to a charity of his choice and auction off the green shoes.