You obviously don't have very much experience with Law Enforcement. A cop can arrest you for "moping with intent to creep" if he wants to, and there is really nothign you can do about it, until your lawyer gets you in front of a judge. And by then, you've paid several hundreds (if not thousands) of dollars, had your reputation ruined, and maybe even gotten into trouble with your employer--all for nothing.
And cops that do this sort of thing usually do not get punished for their behavior. In fact, some departments actually encourage this sort of thing, because even if the case IS thrown out by a judge, you still have to pay court fees, so even if you win, you lose (but the system "wins"--your money...)
Most cops don't know anything about vaping. Some are going to assume that if you are using a device and blowing clouds of "smoke" and it doesn't look like a traditional cigarette or briar pipe, that you are doing something illegal, and THAT alone is "probable cause" to insert you into the criminal justice system.
The police are NOT your friend anymore. They are primarily there to collect revenue in the form of fines and fees, and to get as many people involved in the criminal justice system as possible, because there is HUGE money in the system. And also, most LEAs in major cities are nothing more than mercenaries for the Banksters that own and run their governments, and so they actually benefit from stripping you of your rights by criminalizing your everyday activites.
Wake up, bro. The game has changed DRAMATICALLY since the days of "Andy of Mayberry". The government has officially declared war on individual freedom, and the police are their foot soldiers...