League of Legends has a serious security problem: denial of service attacks. Some of these attacks are against the game as a whole and bring down the whole system. Presumably Riot can eventually protect their servers from that. Worse are targeted DDoS attacks against single players; it’s not clear they can defend themselves
The motivation for attacking individual players is ugly. The game is very competitive at the highest levels of play, with prize money and pro careers on the line. Knocking an opponent offline or just lagging them is enough to get a win. Even if the game is thrown out as invalid a DDoS is still way for a losing game to be converted into a tie.
There are guides on how to avoid being a DDoS victim. They boil down to “don’t reveal your IP address”, which in practice means “don’t use Skype from your real IP”. VPNs, playing only from Internet cafes, etc are other options. But these are minimal solutions at best; hiding your location from the world is really difficult. There’s new rumors the whole IP identification part is entirely automated and foolproof.
I don’t really know how a normal Internet consumer can protect his ISP from being knocked offline with a DDoS. It’s an ugly situation.