[gavanm]

I'm not sure if the video covers it, but I do recall reading that in Madagascar, they mark the beans with pinprick initials so that it's easier to identify if they've been stolen.

https://www.vanillabeankings.com/blogs/recipes/vanilla-bean-...

I might even have read about it originally from here.

Of course that only helps if they're recovered / identified quickly - once any significant amount of co-mingling happens then it's probably too much effort to track down the origin.