I'm surprised someone remembers this, considering how long ago it was, the fact that Valve publicly denied this later, and that most people (on the side of publications reporting that situation initially and outside observers on reddit and other platforms) didn't understand/didn't care for the difference between linux user account names (that caused the bans at that time), steam display names, steam account names and steam custom profile urls.

I have a suspicion that that was FUD spread by the cheat creators. Back then I decided to test that by creating a user named like that and running Steam from there. My account did not receive a ban.

It was real, but maybe the username wasn't the only data point they used. Considering that:

1. Brand new Steam accounts were banned after logging in to Steam client, before even launching any game

2. Replacing "catbot" in user accounts with a random string stopped the bans completely

3. A linux VAC module, dumped similarly to the method described in the article, had access to usernames - I think it was via a getpwent() call. It also collected some other info about the environment (I don't have that binary anymore).

You can probably agree that user account names played at least some role in the bans, even if they weren't the only factor.

* I can't provide concrete evidence for either of those three points as the events took place 8 years ago, feel free to not take my word for it. Maybe you can find someone else from that circle who still has dumped VAC binaries, links to the empty banned accounts or a clone of bot orchestration software repository with a commit that renamed the user accounts and stopped the bans. Maybe even chat logs from that era.

Anyway, at this point it's just a funny piece of tf2 cheating history that has zero impact on anything anymore. So you might as well think it was all fake and I'm just making stuff up, it doesn't matter.