I very stupidly sold my M60s via ebay to a guy in Alabama. Stupid because I wish I still had them and because FedEx dropped one of them on its head.
Long story short, they picked up the damaged M60, completely destroyed it and returned it without comment to the buyer. Boy was he bent. To their credit, FedEx is sending me a check to cover the buyer's purchase price and shipping costs, but now he's stuck with one M60.
Moral of the story: don't sell good speakers; if you do, make sure you have the original packaging (though it may not have helped in my case) or insist on local pickup and settle for less $.

AAAARRRRGGGGHHHHH!