No, I'm not going solely on that- and yes, LL *does* occasionally ban first and ask questions later.
Ask Damien Fate, of FATEwear fame, about having his account seized temporarily, because he named a piece of clothing Marilyn.
I've been in LL a decade this April, I've known numerous Lindens, I've owned sims, dealt with Concierge, and so forth. I know how the system works, better than most- and I know what the usual response is, in these instances, and this is exactlly it. We tried numerous times, in the pre-JIRA era, to get them to add the ability to decline fund transfers, for exactly this reason- this isn't the first time this kind of thing has happened, by a longshot.
Edit: The accounts are on Administrative Hold, not an actual ban- but, regardless, it's still a hamfisted way of handling things, and punishing users who had no way to not be the victim of what was going on.
The incident tonight took place in a public club, and a large number of people- everyone who got passed funds from the random hacktwerp- got dropped simultaneously, whether they knew each other or not. The *only* common thread among them was that they were randomly targeted by the person in control of the avatar when it happened.