One trick spammers use is to register and do nothing. Their trick is in getting their promoted web site noted, picked up by Google and other crawlers.
They often do that by hiding links in plain sight, in signatures, home page links, interests; things no one will usually see or spot unless looking at profiles, but which is often public information which crawlers will crawl over.
We seem to have a few of those hanging around here ...
https://www.raspberrypi.org/forums/memb ... art=108950
Might be worth passing that on to the Admins. I'll report this post so the mods see it.