Most people cannot, believe that they cannot, or would not even if they could. We can be sure of that because despite of billions of cameras in phones, pocket cameras or webcams being out there, the web is not flooded by pictures like these.
Putting filters into cameras definitely works. It is not an obstacle to the determined but it prevents most of the abuse most of the time.
I already do that, because I image nebulae and galaxies and sometimes landscapes in infrared.