Second Chances

It's not autoban. Assuming it's still true that perma ban is only done by live GM.
It does seem to be the result of lazy GMs doing sweeps and just banning everyone in certain maps, or everyone who "loiters" in those maps too long. They might also have converted autobans to permanent without checking the evidence. Either way it seems to be a procedural error that shouldn't repeat itself since it gave Nexon a big headache.

I highly doubt most of these were done by GMs. We know from various sources that banning isn't (or at least didn't use to be) as simple as sweeping out everyone in sight, they need to have reason+evidence. I certainly can't think of any suspicious activity which would've occured while I had my character just standing there. It would've made a little more sense if I had been in a map with monsters but I wasn't. Besides, permanent Misconduct ban should be something that comes following several 7d/30d bans if their ban definitions are anything to take reference from. Not something you get out of the blue on an account with no previous ban history.

Nevertheless, it's always better to be safe than sorry, and you've nothing to lose by not afk'ing in those spammer-infested maps.

As a part-time henehoe it's hard not to. And there's a problem if you cannot leave a regular store in FM without the risk of getting permanently banned (significant part of these afk-bans happened in FM as well afterall).

It's hard to explain these bans to someone who wasn't affected, but as far as my case, the cases I know and the GM reactions for those unbanned go (no ban reason was given), these certainly seem like autobans.

EDIT:

We will be monitoring all unbanned accounts for hacking and other inappropriate behavior and actions. If we determine someone has violated the rules then their account will be permanently banned. We don't expect all unbanned accounts to be good community members but we do believe the vast majority will be.

Vast majority will be? Yep, because they know they false banned people.