Answer by DaveC ·
I think the only thing that has changed apart from me having less time to check in for the past week or so.
I've turned on Recaptcha for new and low-ranking users. Hopefully no one who's been here a while should ever see it, but newbies will need to fill it out to post and sign up. I suspect a lot of the spam is fairly manual, but it might annoy them at minimum.