I look at this like a traveller in an airport - I am responsible for what’s in my bags, for packing them, securing them and ensuring there is nothing illegal in them.

There have been many miscarriages of justice that were the result of someone skilfully slipping something into a traveller’s bag. It is unrealistic to think that a bit of vigilance is all that’s needed. If that were the case, there’d be no pickpockets and mobile-phone thieves.