i travelled with the new passport pouch through london heathrow (LHR) and security asks you to place your documents in the bin to send through the x-ray machine. i said i have a passport pouch and they said it needed to go through the x-ray machine as well.
it was a very quiet sunday afternoon - friday and monday are bank holidays in london this long weekend, so the airport was quiet. but it seemed that LHR was pickier than the last few times i've gone through there (perhaps because they aren't busy). my mostly empty 4oz tube of toothpaste got thrown out and they made me take a sip of my son's benadryl.
the new passport pouch is awesome, by the way. it very nicely accommodated 3 passports and 3 boarding passes.