Riot has plugged a hole in League of Legends and warned of serious repercussions for those who slipped through while it was open.
In a post on the MOBA's forums, community manager Tamat said those who used the so-called Mastery Exploit are in for a rude shock.
"We have comprehensive logs and data that allow us to see precisely who did what, and also who was negatively affected by this malicious behavior," he said.
"We’ve identified all of the players that have been using this exploit, and we’re going to be taking firm action against their accounts. As we continue to investigate and further analyze data, our primary commitment is identifying players negatively affected and doing everything within our power to make it right."
Tamat explained that Riot knew about the issue earlier than it let on, but deliberately deleted forum threads on the subject to keep the exploit on the downlow until it had a fix.
"We take this seriously. Nothing is more important to us than the sanctity of our game, competitive or otherwise. As soon as we discovered the issue, we immediately dropped everything to find both immediate and permanent fixes," he said.
"I'm happy to report that the immediate fix has been implemented, and we'll be restarting all regions this evening to add some redundancy which will prevent similar exploits in the future."
Cheating's a curse on any game, of course, but League of Legends' growing importance on the eSports scene makes it particularly important for Rio to lay the smack down as soon as possible; the MOBA carries the largest purse in competitive gaming.