Aion is going to have a change in an upcoming update to help keep bots from monopolizing the game's resources. On paper, that sounds great, but they decided to implement it by putting a debuff on the player after gathering, which is removable by answering a captcha.
While combating bots is a good thing, I think this is a very poor and laughable implementation. I'd prefer it if they did something that was in the context of the game. Age of Conan, for instance, sometimes spawned NPCs that would attack you when harvesting, like bandits or druids [angered that you were felling a sacred tree or whatever]. They posed little threat to a player that was paying attention, but a bot would be taken down eventually.
A better alternative would be to make harvesting/gathering involve a mini-game, like the ones in Free Realms.
Devs, if you really want to combat bots, just make the gameplay fun. Don't make crafting and harvesting a simple matter of clicking on a button and waiting. Make it something you have to play and react to.