It is best to simply think that all players are out to rob you and put everything behind lock and key.
I for one tend to ask in several chatrooms if the owning player is online, if not I make the determination of "can it temporarily fit in my vault" and if it cannot I do it the old fashioned way... Leaving the disk at the machine, which can be very annoying considering it takes a whole freaking lot longer to get what I want some times. Only have this problem with the T1 Azulyte on Lesser Aradoth. All other locations I already do from disk.