I used to get these on an almost daily basis.
I just blocked everyone in them.
Out of all the idiots who are in these every time, I still get no invites and the ones left blocked are:
NickTheSushi, Pnobio, Zoneark, and MegaScience Although he's more blocked just because he messages me with scripting questions that have incredibly obvious answers, and if I give him the solution he says he's tried it or it 'obviously won't work like that' or something. Like one time on a server with a chat that uses messageAll instead of chatmessage functions, he said that obviously clientcmdchatmessage was still being called despite that it loving isn't, he spouted stuff about this at Jimmg and I for about an hour. Or he just spams stuff about Bioshock.