The end of the 2017 Steam Summer Sale also marked the end of the line for more than 40,000 Steam users (opens in new tab) who were hit with the Valve Anti-Cheat banhammer. The big swing took place on July 6—the Summer Sale ended on July 5—and is far and away the biggest single-day ban wave in the history of Steam, nearly tripling the previous mark of 15,000 bans that was set on October 12, 2016.
As noted by Dot Esports, the timing almost certainly isn't coincidental. It's no great trick for a banned Steam user to set up a new account, but the cost of re-purchasing lost games can add up pretty quickly. The obvious solution is to wait for a big Steam sale and grab them up on the cheap, but doing so seems to have the unintended side effect of turning these recalcitrant ne'er-do-wells into big, bright targets for a re-ban.
Another 5,000 in-game bans were meted out on July 6, on top of the VAC bans, and according to vac-ban.com, the total value of the CS:GO weapon skins lost as a result of these bans was nearly $9,600. The VAC ban rate has since settled back to a more reasonable rate: On July 7, the day after the big spike, 954 VAC bans were handed out, while another 735 were delivered yesterday.