[atonse]

I can't speak for the specificity of parent's "evil maids" phrase but the concept of an "Evil maid" is used in security scenarios.

A maid tends to be an example of a person who's mostly a stranger, but is given unmonitored access to your most private spaces for prolonged periods of time. So they theoretically become a good vector for a malicious actor to say "hey I'll give you $$ if you just plug in this USB drive in his bedroom laptop next time you're cleaning his house" - it's often used in the scenario of "ok what if someone has physical access to your resource for a prolonged period of time without you noticing? what are your protections there?"

I wonder if that's what OP meant? :-)

[gritzko]

"Evil maids" (example): I put my laptop into a safe, seal the safe, seal the room, go to breakfast. On return, I see there was cleaning (not the usual time, I know the hotel), the cleaner looks strangely confused, the seal on the safe is detached (that is often done by applying ice; adhesive hardens, seal goes off). This level of paranoia was not my norm. Had to learn these tricks cause problems happened (repeatedly). In fact, I frequented that hotel, knew customs and the staff, so noticed irregularities.

[selridge]

And what does this have to do with the price of tea in China?

[ctmnt]

Ah right, thanks! But it seems he meant literal evil maids. Which I guess count as the figurative kind too.