It is basically already illegal everywhere in Germany. German law has these things called "the right to your own image" and "the right to your own voice". Basically if I want to film or photograph you, I have to ask for permission first, even and especially if you're out in public. There are exceptions for if the person is incidental to the image (I photograph a building and you just happen to walk into the shot) but these don't really apply when riding the bus. So using the glasses is already illegal. This is about wearing them.

Side note, this is also why Germany doesn't have as many private security cameras. Because you need to place them in such a way that you don't film the sidewalk, which is complicated. And it's also why German media doesn't use secret phone recordings. It's always a "recollection from memory" re-enacted by a voice actor.