"Bob Gardner" wrotet.com:

It's not the TSA, it's the air carrier. The regs place the
responsibility for approving portable electronic devices on the pilot
in command, but in most cases there is a company policy that the
captains go along with.

The REAL regulation..........:-)

(c) In the case of an aircraft operated by a holder of an air
carrier operating certificate or an operating certificate, the
determination required by paragraph (b)(5) of this section shall
be made by that operator of the aircraft on which the particular
device is to be used. In the case of other aircraft, the
determination may be made by the pilot in command or other
operator of the aircraft.