I had my 15-watt soldering iron confiscated in Chicago and when I offered to leave the sharp chisel and point tips behind so that I could take the iron, they said, "Oh, those tips are fine, but, the part that plugs in can't go." I asked whether they thought I was going to take it into the plane's lavatory, plug it into the non-functional electric razor power outlet, and then come out threatening to brand someone in the seconds before it cooled off. When the agents gave each other the "Prepare The Back Room" look, I shut up and left it behind, only grumbling loudly after I was out of earshot of the security area.
On another trip, I had a large number of very small Z scale model railroad locos (each as small as an inch/25.4 mm long), rolling stock cars, and their digital command control (DCC) power pack, controllers, associated wiring, track, etc., they wanted me to take it out and show it running ... not because they thought it was a security risk, but, because they were model railroaders and wanted me to prove that something that small could actually run!
The best things in life aren't things ... but, a Pi comes pretty darned close!
"Education is not the filling of a pail, but the lighting of a fire." -- W.B. Yeats
In theory, theory & practice are the same - in practice, they aren't!!!