What's your agenda behind looking at this page?
Joking aside, I've been met with this question quite a few times and in other cases with assertion about the answer, so I thought this funny little thing earned the right to have a wiki page. -- CostinCozianuWhatsYourAgenda is a very funny question, especially when the one asking it is running out of arguments. It usually implies that the one being asked is a dishonest person and has a hidden agenda behind his actions.
Just to ask it doesn't make any sense at a close analysis. Even if you suspect that the person you are asking is dishonest and has a hidden agenda, that's not the right way to tackle the problem, go find some logical arguments instead. And in any case you risk making a fool of yourself.
Especially since the question automatically fits in the AdHominem category.
Everyone has an agenda - that is, a reason for doing the things they do. Knowing people's agendas can help you resolve conflicts and avoid problems. Asking "What's your agenda?" isn't usually a good idea, though, as it's confrontational and implies that you think the person is hiding something.
If you get asked this question a lot, it's probably because people can't figure out why you're doing the (typically irritating or disruptive) things you're doing.