Only one, which was found in a green glasses case next to Mr Shrimpton’s bed, was found to have contained deleted files, 40 of which were found by police specialists to be indecent images of young boys.

...a classic cybercrime-and-espionage hypothesis is to litter USB sticks in the parking lots and such near sensitive target areas, and hope one gets lucky.

It would be... trivial... to repurpouse this. 'n unlike a code package, they could be "empty."