I've received a message about webcam sex BS from a user "Werytuifdsa" with whom I haven't spoken before. It came out of the blue and looks like spam. Is there a thread or a process for reporting these spammy users?

Well, normally a PM to one of the mods tends to work...it's important info, actually, since MG has had issues with spammers that've required site filter adjustments.

However...have you considered the "abuse potential" here? Try messaging them back with loads of technical gibberish, such as inquiries about the CV interfacing for the webcam so that you can sonify your websex and possibly make some money off of their own scam. Or ask them if their websex "providers" respond to all MIDI sysex messages, including poly-aftertouch, because...quality websex should have poly-aftertouch. Etc etc etc...

Or just have the mods block 'em.

Sorry for the issues. Sadly the messenger had no spam protection so Werytuifdsa was able to send her offer to ca 2000 users and killed the SMTP doing that
We now have a limit for standard users: they cannot send more than 3 messages per hour.
Limits, fences, borders everywhere, it's not what I had on my mind ...