Be careful with any USB drives you take to photo kiosks — thoroughly scan them afterwards for viruses.
Turns out Big W (FujiFilm) kiosks have been spreading viruses, and Fuji is now investigating equipping them with malware protection. Not before time.
This rung a bell for me. I’m sure a month or two ago after I got some photos, I found the drive I’d used had a suspicious autorun.inf file on it that I could’t figure out the origin of.
As Graham Cluley comments, it might be best to use a USB drive with a read-only switch.