Untrue - if you see something that look suspicious, please let us know via support ticket.
Hoof, wouldn't it be better to build the game mechanics in a way that does not invite cheating so much? It's the same issue as the GvG problems. You introduce a feature and when it's discovered that contrary to your expectations, it's being abused, your reaction is repression and limitations (and in this case "yes, we'll gladly reward the cheaters by an automatic system and if you think they're cheaters, please open a support ticket so that both you and we will have to waste time in administration").
What is the likely outcome? Unless the cheating recruiter is grossly stupid to do things from his own IP range, they can always say "I don't know who did it" - and you can either punish them anyway (and open a door for some very nasty revenges, because ANYBODY can fake recruits of anybody else) or they'll get away with it.
Why don't you reward people for bringing other real people into the game and making them stay? How hard would it be to give recruitment rewards only for recruits that stay several months? Bringing accounts is not anything that should be rewarded, as opposed to bringing new players!