Just report them.
Not telling you how to do your jobs or anything but I think deleting the posts and giving the account a security ban would be much more appropriate in dealing with this incident just in caase someone remembers owning that account and questions why they were blocked from the forum at such an early time...
What do you think we do with them? Politely ask them to stop and offer them a back rub?
I believe what he means and what I also have witnessed many times, is that people clearyl deserving a ban rarely get banned fast when reported.
I have myself reported some spammers several times. Their posts got deleted in a timely fashion, but they wouldn't get banned for a few days while it was being obvious it was automatic posting.
In more obvious terms for hilarious: “don’t nuke it, delete the bad posts and give it a security ban so the original owner can cone back and unlock it if they reveal themselves and prove actual ownership”.
But actually, if it’s on the alts board stuff gets dealt with quickly. If it’s elsewhere then good luck to you! Let’s hope it gets deleted by a few weeks.
(Slightly off topic: who’d want a back rub from you hilly?)