As a retired LEO of 27 years service, I can sadly relate to some of the worries and experiences listed in this thread. When we live in an era though that everyone from Google Maps to the Fed's are able to watch us 24/7, you are subject to be hassled for any or no reason at all.
One reason I retired when I did was the fact that new recruits for Police are generally recruited based on the willingness to do as programmed without thinking. That in our situation simply means that any cop that sees you
vaping, especially with a
mod, may stop you based on the visual similarity to a .....
That said, they still have to have probable cause to do more than check what they see. It doesn't give license to search or sieze. Once stopped, if a cop has no smell of ........ or other court proven "suspicions" of illegal activity, the worst they can do
lawfully is to waste a field test kit on your gear.
Even if they come off as hostile, don't give them a legit reason to give you a hard time! It is
hard, especially for someone like myself to not call and ...... just that, an ....... Over 27 years though, I saw many times when a simple situation escalated into a legit violation because a citizen became physically confrontational. I never worked traffic enforcement but I have been stopped many times and had to bite my tongue over some jerk with a 10 pound badge.
Almost all states have dash cams in cruisers to document traffic stops and the same camcorder that makes a legit case can also expose an illegal action by the cops themselves. Just remember to keep your cool and if the cop goes beyond the realm of reasonable behavior, there
are legal recourses for you to make sure jerks with a badge don't keep their ability to harass.
For even the most sincere, most have never even heard of an e-cig, much less seen one in action but for most dealings, keep your cool and you wont have any issues no matter how irritating it is to be stopped.