It looks like Call of Duty's anti-cheat is permabanning innocent players

Call of Duty players are saying they're getting banned from the game over false positives from Activision's proprietary Ricochet anti-cheat. Now, I know what you're thinking: oldest story in the book, that's just what John Q. Aimbot would say with his hand caught in the proverbial cookie jar. 

However, the sheer number of these claims, as well as the common details shared between them, leads me to believe there's something amiss, and these paying customers have been left frustrated by Activision Blizzard's stony response so far. The company did not respond to a request for comment in time for publication, but we will update this story if we hear back.

Mike Swanson, a former Microsoft employee and self-described casual player, published a blog post covering his experience with Modern Warfare 2 on December 5. Swanson describes encountering a sequence of crashes while playing MW2 and giving up on further play that evening. Upon trying to play the game the next day, Swanson found his account banned. It's also worth noting that Swanson, as well as a number of other claimants, say they only play Call of Duty in singleplayer.

His attempts to appeal to Activision resulted in a sustaining of the ban on review, with Activision claiming to have discovered use of "unauthorized software" and "manipulation of game data."

Swanson also directs readers to a highly rated Steam review of MW2 from user Necron242, and this account shares many details in common with Swanson's. Necron also says they were banned for "manipulation of game data" following a short gameplay session ending in a crash. Crucially, Necron's review shows that they had MW2 successfully refunded despite having four hours of playtime logged. Steam's refund window is within two hours of play and two weeks of purchase, meaning Necron made an appeal that was sustained by Valve. 

"I explained the situation to Steam and included the correspondence with Activision Blizzard," Necron elaborates in a later comment on their own review. "I also sent them the news articles of this happening to other people"

I've found similar throughlines in stories from other players. These Reddit threads from users Bender99342 and jbop15 report similarly low playtimes to Swanson and Necron, and the comments also contain even more users complaining of mistaken bans and denied appeals. Activision Blizzard's page on the Better Business Bureau website is full of complaints about false bans, and there are further accounts on the Modern Warfare 2 and Activision subreddits dating back to the game's launch.

Bender and jbop's posts include screenshots of the in-game message informing them of the ban, with a given reason of "Caserma-Rhino," which seems to be Activision's internal code for a user manipulating game files or using cheating software, and a quick search of the term results in more examples of confused users complaining of mistaken bans. 

There could be a number of reasons why players could get falsely flagged for using external cheats. Both Mike Swanson and Necron 242 posit that peripherals software like GeForce Experience, MSI Afterburner, and Razer Synapse could be getting incorrectly flagged by Ricochet anti-cheat. 

Modern Warfare 2's documented stability issues could also be a factor. Swanson writes, "As a developer, my personal theory is that the frequent crashes (and accompanying errors about corrupted files) are being incorrectly flagged by the Ricochet anti-cheat software as intentional manipulations made by players." Necron242 and multiple other users report having attempted to repair or verify their installations of MW2 shortly before being banned.

Absent official word from Activision Blizzard, it seems players' only recourse is an extra dose of caution when verifying their installations or using peripherals software, but this is hardly a guarantee. As for those already affected, people who purchase MW2 on Steam have had luck requesting refunds from Valve after having exhausted their options with Activision Blizzard, while Battle.net players have no such option. Mike Swanson, meanwhile, is attempting to organize claimants for a class action lawsuit against Activision Blizzard via Discord.