I’m not saying it’s a real danger (people willing to do that could already do a lot of other stuff) but I wouldn’t be so sure that you couldn’t do it either.
You can already pretty easily handcuff a drunk person and then draw all over them with a sharpie, and that doesn't take 15 minutes of leaving a patch alone.
Obviously doesn’t really make sense because if it’s an ad you also know who did it but somehow that’s the first thing that came to mind for me.