I'm tossed on this one. While I fully believe that we do have the right to bear arms, and where applicable, openly; there is an element of "Let's see how far we can push the envelope" here. There are several videos like this out there, and you get different people who respond in different ways. This policeman in Missouri doesn't appear power hungry, just kind of gruff. He probably responded to a call that there were people in Walmart with guns...who knows what the call in sounded like. In that case, the backup with the AR-15 would be support...and he puts it away toward the end of the video understanding it is not a threat. They didn't draw on them and they didn't try to confiscate, but they did want to make sure it was on the up and up.
Seems these people feel we should just be able to walk anywhere with pistols, rifles, semi-auto's out and open without people freaking out. If we didn't have things like Aurora, CO, the Navy shootings, etc... that could possibly happen. Unfortunately, those things did happen, and when people see open guns they generally freak, call the police, and they have to respond. If you have nothing to worry about, handing over an ID to prove that, A) You are allowed to carry and, B) You have all registrations and aren't a criminal, shouldn't be a big deal. That a police officer wants to make sure of these things is not playing "Nazi" or power hungry. They are already registered gun owners, so they are not being added to any secret database file...they would already be on it. If the officers take it to the next level and arrest with no cause or confiscate properly registered weapons...then that would certainly qualify.
I am all for gun rights, the right to carry, etc...but bringing open firearms into Walmart to see what happens, or walking down the street with an AR-15 strapped to your back for the same reason is kind of asking people to freak out on you.