Originally Posted by Loren Pechtel

Yeah, I hit one boarding a train. I totally wasn't expecting it, my film wasn't packed for easy removal. Stopping and removing it would have made a big snarl (there was no place to get out of the way, even going back to find a space would have snarled things up), after a moment's thought I simply carried the relevant bag around it intended to explain to security what was up if someone squawked. {My wife is a native speaker, the usual language barrier wouldn't apply.} Nobody noticed.