pros:
Clueful people's lives will be easier, especially because such lists are notoriously wrong and/or overzealous and there are several of them so it's hard to figure out which one you'd have to yell at to get removed from. That is assuming that there actually is no open proxy issue. If there is a genuine open proxy issue.. well then it won't hurt things.
cons:
Err.. AOL users will bombard them with emails spewing uninformed rhetoric? I rather doubt this will happen.