Question for the #fediverse #admin community. I have a few tiny instances -- #pixelfed, #friendica, and #peertube -- mostly for friends and family, but I've let a few random strangers join (mostly before I started getting lots of obvious spam accounts). I've noticed that these accounts have no posts, no activity, but don't have the obvious hallmarks of spam accounts (no get-rich-quick links in their bio).

Is there another angle here that I should be aware of? I'd hate to find out a year from now that there's some common scam or attack vector that I'm enabling that I'm not aware of.