Then they use the platters as coasters.
Good taste not guaranteed...
I already knew about credit card skimming but now it's getting more and more sophisticated!
He did a similar prank some time ago but with drug dealers
Remember this video? Well Captain Disillusion here explains it all
That's quite simple, you just need to remove the polarized layer from your computer screen and use new polarized sheets to make polarized glasses out of 3D glasses for example.
Only the person wearing the special glasses can see what's on screen, others will just see a blank monitor.
Better try that first on a used monitor you don't care about though...
Whatever works, I guess, when you don't have proper equipment.