[ThinkDifferent]

That isn't difficult, particularly if I have access to the network segment on which the machine-to-be-attacked resides.

You *must* have access to the same subnet as the target. You can't attack a random Mac on the Internet with this technique. The main threat seems to be for the Starbucks wireless user.

[Bush2000]

You *must* have access to the same subnet as the target. You can't attack a random Mac on the Internet with this technique. The main threat seems to be for the Starbucks wireless user.

Not just Starbucks. Any LAN/WAN environment that has Macs connected to it that uses DHCP -- which is nearly all of them.