You can stop it...Here's how I stopped it on my network.
I control ALL members that wish to join. The members that don't fill out the profiles, and keep them blank, and when the network owner (being me in this case) tries to check the email address, it's a "spam" address,..........then I simply do not allow that member on.
I was receiving at least one of those spam members a week until then. Now, I rarely get a person that tries to join my club.
That would mean that the owner of this club would have to be proactive.
yep.
Here is how I prevent this kind of kr@p on my network.
I first come up with questions that must be answered and known by those involved with my game.
Second, I oversee accepting all ....in fact, I just accepted someone,...wasn't sure about them, stayed around a few moments and sure enough they tried spamming.......bamm, immediate ban.
So, I guess you not only have to have someone accept members, but you have to have admin's who play watchdog once in a while...