May the police conduct an investigative detention after observing a presumptively lawful act without additional information to suggest that criminal activity is afoot?

Pennsylvanians are being detained for participating in a presumptively lawful activity —wearing a single earbud headphone while driving. This egregious encroachment on American’s Fourth Amendment protections is an expanding epidemic across the United States, causing a sharp divide between the circuits. In some jurisdictions, where the legislature designates specific conduct to be lawful under an exception or pursuant to an affirmative defense, the police are permitted stop these individuals and demand that they demonstrate their conduct comports with the exception or defense. This scheme is offensive to the principles that underlie the Fourth Amendment. Rather than demonstrate reasonable suspicion that criminal activity is afoot based upon objective facts and circumstances, the police may simply stop anyone for participating in a lawful act and force them to prove that they are not acting unlawfully. The question presented is: May the police conduct an investigative detention after observing a presumptively lawful act without additional information to suggest that criminal activity is afoot? i