I've already mentioned the problem to theymos on a number of occasions though aside from a few blacklists (which would help if they weren't just *a few*) and the tightened PM restrictions (which don't really matter much since dropping a few cents on a captcha bypassing API isn't that much when your services are (probably) paid for), we're kind of left to fend for ourselves on this one. I (as well as hilariousandco) ban these accounts when someone reports the PM spam and that is as much as we can do.
If it was easy and simple to make them stop then I'm sure theymos would have done it by now. I agree that they're hugely annoying and staff get spammed with dozens of reports on them every day and something does need to be done to prohibit this. I think we should consider prohibiting brand new accounts from PMing people and possibly bring back newbie jail in some capacity. Maybe for all users their first post can only be in newbie jail/beginners and help or users need to be whitelisted before they can move out of there. Any question they have can be asked in Newbie Jail and it will then stop the rest of the forum being plagued with ref spam and people asking about the same questions in Meta day after day.
I've recently PMed theymos with a few suggestions though he hasn't responded yet (to be fair, it's only been 2 days or so). IMO, considering the sizeable number of rather user-unfriendly restrictions already in place (relatively performance heavy (especially on mobile) login captcha, strict PM limits, lackluster account recovery process (coupled with a severe lack of account security features), a bunch of disabled SMF features), I'm rather against any heavy handed restrictions that'd hurt the innocent users more than the spammers.
Does the SMF software allow you to pick up on certain words in a PM?
If so then perhaps putting a ban on all PM’s from brands new members with 0 posts which include the words ICO/token sale in them.
I’m not sure if there’s an option for specific parameters but if there were then it could be a possibility.
I get them fairly often and when I see on my email notification that the PM was from a new member (no preview) then I just don’t bother looking at it at all.
Not sure, maybe. If it does, it's an admin level feature.