Not to rile any feathers and it's no secret what I do but here is my take on the whole situation.
They were wrong to confiscate the camera. Look on youtube and you will see people video taping agents because they hate checkpoints (it is an inconvenience to they illegal activities in my opinion). It's not too difficult to ask the scout what he took a picture of and if the agents face was on it, ask him to erase it because he did not authorize his image to be used. Done deal no need to go further.
If a scout left the area and attempted to grab a bag from the van or roof of the van as stated, how would you feel about that if you are an agent doing a search of the vehicle? Was he grabbing it because he had drugs and didn't want the agent to find it? Was he carrying a gun that he either didn't want the agent to find or was going to possibly use it? Or was he simply just grabbing his bag for a snack or an extra memory card or extra jacket to keep warm? No one knows the answer to that and officer safety is a big concern as is the chance that the scout maybe trying to hide something. Did he go too far? Posssibly if he did infact pull his weapon. But the whole gun pointing thing would have been avoided if the scout had not tried to retrieve a bag during a search.
We don't have all the details like why did he want his bag, how old the scout was, what was the purpose of the search. the story is sketchy. Those are answers the video can show and address.
Not saying it's right, but when I'm at work, I don't like anyone behind me or behind my partner, its a safety risk. I also don't let anyone go thru their bags, once again because it is a safety risk no matter how young or old they are. It's sad that we live in an era where you don't know who is a risk. I remember when I was in 7th grade and hearing about schoolmates doing drugs and drinking. Now it seems to be a common practice. Reading about how some kids go off the deep end and use weapons. We are living in an era where being vigilant is important. It's sad if you think about it.
Like I said, I see a lot of things wrong with how the situation was handled, but can understand why they don't want someone trying to get to their bag during a search. If he did pull his weapon, yeah the guy is a little too high strung and needs an eval. If they threatened the scouts, yeah they need to be better trained on how to handle a situation when a picture of them is taken. There is a lot where more training or better people skills and communication would serve in aiding to prevent situations like this.
be nice to know the truth and see that tape.
Anyways that's my take on it. guess
i'll wait to be called an ahole for thinking safety first regardless of who it is. 
Kique
