watermarked multitrack files from studio, scare tactic or reality?

I used to work as an intern in a major studio in the US and maybe technology has changed, but watermarked studio files used to mean just adding another audio track over the top to prevent stealing the music (clicks,beeps,tones etc)
I've been told that digital studio multitracks now can be traced back to origin of who licensed them. So let's say so and so's company licensed some tracks from a label the project never happened or company went bust, they still have the tracks and gave to a friend who remixes. Can those files be traced back somehow to the licenser?
If anyone knows for sure chime in. I've asked as many industry people as I still know and some say it's just bs scare tactics to prevent theft and misuse of the label assets. Just curious
thanks :)

I have heard the same exact thing. Some labels told me "this file is watermarked, any use other than to remix for us will result in your balls being cut off" etc. There was one time where they said it's watermarked, and if I share the file they will find out. I "accidentally" shared said file, no one ever noticed. From what I hear, it's watermarked but only a certain spectrum analyzer is able to see the watermark. Even after the file has been remixed.

Have you tried opening those files in audio editors that allow spectral visualization? Maybe you could see the watermark there?

Some ten years ago Depeche Mode's album leaked before official release and it contained a watermark that sounded like a glitch. That doesn't seem like a very good protection. But things may have changed in the meantime...

An audio watermark is a unique electronic identifier embedded in an audio signal, typically used to identify ownership of copyright. It is similar to a watermark on a photograph.
THere's even a way to put a QR code on the spectrum of a track, that way labels can track easily who leaked the files :)

So what is the deal with stems/multitracks originating from Universal Music Group labels and sub-labels such as MCA/Def Jam-roc a fella etc?
A lot of them say "watermarked" in the filename and when you try to save as mp3 /Itunes on MAC it won't work? It has to be in the metadata, there's no weird audio glitches. hmm..

Can you send me one file that is watermarked (or pm me the way to get them or whatever)?
I'd love to see how they do it and what is watermarked in it. Thanks!

I may even be able to remove it, should I find it.

I believe the watermark is within the metadata like INGSOC commented.