in these past days there is (once again) alot of invite-spamming.
Now usually they invite to channels they just created, but i've seen also invite bots who invite for 'regular' channels like #computer or #americanidol (just two examples).
If you whois these clients, they are always connected to irc.nac.net.
example:
irc.nac.net is one of the two servers which are still running the (obsolete) csircd which allows invites from non-opped clients.· · Invite : to #computers by [ gabbled ]
[ /whowas gabbled ] ————————————————————————————
: › Address : ~cruet@***
: › Name : rosery pearlesce parrakeet cliquish
: › Server : irc.nac.net [ Sat Apr 14 12:08:58 2007 ]
· · Invite : to #americanidol by [ muonic ]
[ /whowas muonic ] ————————————————————————————
: › Address : ~cruet@***
: › Name : rosery pearlesce parrakeet cliquish
: › Server : irc.nac.net [ Sat Apr 14 11:28:24 2007 ]
Now this is not only annoying, but it gets spammers and grievances to regular channels which have no idea of what's going on, since every user can massinvite to their channels.
So my suggestions is to either turn the invite for non-opped clients off on these servers, or update them to a decent ircd.