Why? Glad you asked. Valve have been made to release some relatively sensitive information to the public; you can now look at every single match you’ve ever played in CSGO (From 2012). Going to your games folder on your steam page will allow you to open up a new tab called ‘Personal Game Data’ on a select few games (Including Portal 2, weirdly enough). Counter Strike is thankfully included, allowing you to scroll through the worryingly big backlog of competitive matches you’ve played.
If you’re a statistics junkie, you’ll be able to find out loads of cool information like how many items you bought on the front page, or how badly you predicted the Krakow 2017 Pick’ems. This is really cool, but with an awesome chrome/firefox extension, you can now figure out exactly how many people have been on VACation since you played with them.
Fair warning – You will have to surrender your API key, so do that at your own risk, but it’s seriously worth a look.
The Ban Checker for Steam will trawl through every single game you’ve played and scan every player in those games to check if they got banned after playing with you.
I’ve been playing CSGO for a while now. In my competitive history, I’ve encountered 2991 unique players and 266 of them where VAC banned after being in a match with me. That means almost 9% of players I’ve encountered where hackers.