Police departments freely admit tinted windows are a reason to pull motorists over only to see if there is anything else going on. It's fishing. More Americans need to be horrified by this. If nothing is wrong, don't pull them over.
Advocates say that a person who has nothing to hide doesn't need tinted windows. Ridiculous. Many of these stops take place in states like Florida where motorists have tinted windows against the SUN. Again, more motorists need to fight this.
BUT... tinted windows are an option, so this is an easy fix for motorists who feel a risk in the short term.