Honestly, close doesn't even mean that close. The rules point out that it's illegal to fly within three miles (4.8km) and under 3000 feet (914m) of stadiums from NCAA Division 1 football, Major League Baseball, the National Football League and, err, even big car races. Air space above these places is designated as "national defense airspace" for one hour before and after events — hence the strict penalties.
This is really an extension of existing rules — but it's the first time the FAA has ever explicitly stated that criminal penalties can result from flying in restricted airspace. So, better stick to watching the game on TV, then. [FAA via Ars Technica]
Picture: Bureau of Land Management/Flickr