Several Super Smash Bros. 3DS players have reported being banned from the game for 71,582,030 minutes or 136 years.
Players are usually banned for 15 minutes, but it seems there's been an error with Nintendo's anti-griefing systems. The automated tech was designed to penalise those who specifically targeted a specific player during group matches.
One player has tried to figure out why the bans last that specific number, and the general theory is that there's a simple code error in the programming which determines how long players should be banned for.
Nintendo has yet to comment on the issue, and the only safe way to avoid it at present is to play offline, though one-on-one online battles should not be affected.