So
shimps1 has had his/her account shut down:
AAdvantage Account Shut Down - Recourse/Appeal?
As far as I can tell, he/she has done nothing that others here are not doing. But AA may have decided that opening AAdvantage accounts for ---let's just say "others"---is against the TOS, even if those accounts are not used to accrue or use miles. That's the only thing I can think of. AA gave no reason and the poster has said he/she has not done anything [else] that would be a problem. It should be clear that I am just speculating; does anyone have other ideas?
.