It's a silly rule. If the device is unpowered, you must pack it into your check-in luggage. Since the new rule is aimed at suicide bombers, wouldn't the device be just as effective being detonated with a timer in your check-in?
in that case, all suitcases, and their contents, need to be inspected before check-in. That is a huge logistical effort that I doubt the airlines and airports are prepared for. It is further complicated that you may check-in your luggage at a connecting flight before taking the overseas flight. The connecting flight isn't restricted, and may not be the same airline as the US-bound flight.
There seems to be 3 news in 1 article unless I missed the connection.
The new TSA rule could cause a lot of problem to business travellers. With the rule, who can bring a USB drive? I hope the rule is for short term and will be removed as soon as they find a better way to inspect explosives or other hazard materials.