Problem: some houses and apartments have windows that face neighbours windows. This leads to a lack of privacy.
Solution: an adhesive polarizing film that covers each window. The alignment of the polarizing films are 90 degrees wrt each other, e.g. one window would have vertical polarizing film, while the other would have horizontal polarizing film.
xaviergisz
1
So the neighbors would have to agree to use the film, and agree on orientation?