Playing AK, do any good players just call a raise instead of 3bet?

[flytrap]

I was having a discussion about AK with a couple of decent players, one of which I noticed just called with it on the button after the CO+1 raised and the CO called. I heard the old argument, about it being a drawing hand, etc. Another argument my roomate made, is that is the utg raises and 4 people call, they might have some of the cards you need to improve your hand. I almost always 3-bet with AK, and when I don't, it's because I folded it when the little old lady raised that only raises with aces. In what scenario do you not 3-bet AK?