Limping Aces from EP is a very very read dependant play. That being said at the micro's someone probably saw it on "High Stakes Poker" and is misusing it in his game. If you didn't raise fucker would be in a world of hurt due to the huge limped pot.

That being said preflop is a fold. When you have lots of limpers and you raise and your raise is 3bet than 4bet its time to dump AKo.