17. Catching Someone off Gaurd
This practice of taillight tapping even predates the times of dash cameras and even before body cameras, which are now part of the everyday police uniform in the United States. Police initially started doing this with the intention of catching a driver or passenger off guard, watching their every reaction. It’s not out of the realm of possibility or uncommon for a person to attempt to stash contraband as they are being pulled over, so this can sometimes help prevent that.