The mysterious semantic shift of the word "random"

[AmiablePedant]

Has anybody else noticed this? For me the word applies (for example) to a chance event (a random occurrence) or can qualify a group or set that is constituted without any criteria (participants were chosen at random). But now it seems to mean "something or someone that I am personally unacquainted with" ("the professor made us read some random articles" when the professor in fact had very carefully chosen the readings, it was just that the student didn't see the logic of their presence on the syllabus). Or somebody can object to "random teenagers" hanging out at her house when what she means is "friends of my teenage children whom I don't really know"--but not teenagers wandering in capriciously off the streets and perpetrating a home invasion!
I just needed to get this off my chest . . . .

I think this shift happened a while ago. I'm sure we were talking about "some random bloke" back in the 90s.

Yes it's been in use for a long time. Not sure if this 'new' definition has entered the dictionary, though. It's interesting seeing how fast language changes, words fall in and out of fashion - and change meaning altogether.
I can imagine a dictionary in 50 years time. 'Random. A chance event (now obsolete).'

There's an episode of How I Met Your Mother from 2010 in which the group is horrified that Ted has brought his new girlfriend to Lily's birthday party, and most of the episode centers around various attempts to distract her so that they can furtively take pictures without "some rando" in them. Eventually someone points out that Lily's best friend Robin also was originally introduced to the friend group as one of Ted's "random skanks".

It used to be an interjection, when I was a teenager in the 90s. Probably like kids say daft stuff like skibidi toilet today. We would just exclaim, "random!" to any novel event that happened.