Valve has banned tens of thousands of accounts following the conclusion of the Steam Summer Sale. How many accounts? Well, according to certain database services there are almost more accounts banned than what most indie games sell in a week: over 40,000.
Valve wisely waited until after a bunch of people bought games and after the Steam Summer Sale ended to nuke the accounts from orbit. Some people are speculating that a large portion of those accounts are burner accounts to test various cheat services and memory allocation programs used to inject data into Valve games like Counter-Strike: Global Offensive.
Some people might be wondering why anyone would create a burner account to test programs in Counter-Strike: Global Offensive and end up getting VAC banned for their troubles? Well, a lot of hackers use throwaway accounts to test cheats in games like Dota 2 or Counter-Strike to see what registers on the VAC radar. It's essentially data sampling and collection... hacker style.
The idea is to find out what works and what doesn't, what triggers VAC and what doesn't, and then proceed to build a cheat system around it and possibly sell it. There's an ample third-party gray market for aimbots, loot cheats, and wall hacks for games like Counter-Strike, League of Legends, Smite and Overwatch.
To be fair, though, the bans doled out during this past year's Steam Summer Sale (or rather, directly after it) pale in comparison to prior years. On July 6th Valve banned over 40,000 users, but back in 2016, according to SteamDB, June saw a record number of VAC bans handed out, totaling 176,262, which is well over four times the amount of users banned in the last banwave.
Previous to 2016, the next big banwave spike was only 110,000 back in June of 2015. There seems to be a consistent spike in Valve cleaning out the house of Steam during the summer months, likely due to the fact that a lot of people are out of school and have a bit more time to meddle around with cheats in various games.
This June also saw a pretty high number of bans as well, totaling 127,661. Prior to that, Valve also put the ban hammer on more than 147,000 users back in February of this year.
According to Polygon, the VAC banned also managed to sweep up some number of weapon and cosmetic skins, totaling $8,674 worth of items purged from the system. It's almost like Valve went full ATF on hackers.
Of course, the real lesson here is that Valve doesn't play when it comes to banning accounts. A VAC ban ensures that you won't be able to play online, and sometimes it's restricted to the a game, while other times it extends service-wide, ensuring that your account won't be able to access the online portion of any game.