Thing is the exploit here involves being invited by a seasonal character and then disconnecting, that’s too complex to be done unintentionally besides a handful of cases (specially when it started spreading through the forums).

Perma bans do seem a bit heavy handed (I’d be fine with a 3 days ban for first offense) but…

As I’ve seen it explained recently, these keys are bought using stolen credit cards and resold on G2A. Once the cards are reported stolen the bank/rightful owner demand a chargeback that will hit the developers of the games in question.

Had to sign up just for this shameless plug for Erma, a webcomic about the daughter of Samara (from the U.S. version) in a daily life setting. It’s really, really cute.
Check it out at http://brandontheoutcast.tumblr.com/ ,