I was in a hacking guild not so long ago, we were like 10 players (not all of us had hacks, and I didn't have any at that time).
One day there was a little childish fight between two guys and one started saying he would post pics on forums and submit tickets of the guild leader (since he was mostly hosting our hacking rides because he had a good connection/pc) because he didn't care about getting banned and wanted to quit anyway. We disbanded. Shit happens.
If you want to make one, make sure it's with trusted friends and mature people. And make it small... Having friends that you can't trust gets tiresome. You always lie and such. And sometimes they gonna ask to add to friend list and you gotta create excuses why you don't want to add them, since you don't want them to see you made 15 BL runs in 15 minutes for cash, or 3 labyrinths in 8 mins lol. Or how you got from level 35 to 70 in 1 day and rank 6 skills after a laby run (when we could still use laby exploit). So... good luck with that.
I think having a few friends you can rely on without having a guild is better in my opinion.