Valve has permanently banned 40k users in a single day
A VAC ban is issued by Valve, and stands for the Valve Anti Cheat system. Players that are detected to using third party programs such as scripts or hacks will be detected, analysed and then banned for good. These bans can only be reviewed and reappeared to be Valve, where steam has no say in removing such bans.
When you are VAC banned, the account you are on will be permanently suspended from all VAC secured servers, meaning a ban in Dota is a ban in csgo.
On July 6th, according to steam data records, over 40,300 players were issued a VAC ban on that day. This is an astronomical amount, as usual VAC per day are typically around 5-6 thousand. This definitely welcomed, as more VAC’D accounts means higher quality games across a variety of games.