Keep in mind that some states, other than MA, require you inform any officer on an official interaction (for example, traffic stop) that you are carrying. This does not always go well - google "Canton ohio harless" to see how it can go bad. And note, that even though the court found the charges bogus, he was fined $150 for "stopping in the road" since the system does not like to go away from a case unfed.
I was in a car with two other folks and the first thing the cop asked when stopped was "I smell gun powder, where are the guns" (I was carrying). 15 minutes and two backups later the driver was told "You are exercising you right as an American to be armed and that is a good thing, here is your warning for the violation". And this was is in a heavy moonbat town.