I guessing it is the same user doing this over and over, making countless accounts to do such stuff, and getting banned real quick.
Actually, the admins have probably given out IP bans (bans that no longer let a person access AG through their specific internet connection) to try to stop the problem. And yet we still have the spam. So whoever is behind all these bots, they are quite smart for figuring out how to circumvent the IP bans and for adapting the bots to beat the CAPTCHA. - Yeah... the CAPTCHA is a failure. AG staff, we all hate it because it's not stopping the bots and it's annoying for the legit users.
It asks beacuse some stupid adbots came o.~ Now EVERYONE on te site has to do the CAPTCH because some n00b spammrs made ads o.o It really isn't that bad though.