This is my feeling on the subject.
When a 12 year old kid comes to an event wearing surplus or family borrowed bdus and has rank, it's pretty obvious that they are not trying to portray themselves as a service member. Hell, I remember being a young kid playing army with my buddies wearing the bdus my uncle gave me from his service in the Air Force. I wouldn't expect someone to take patches off their family's clothing unless they were going to be keeping them, but players who purchase surplus gear that has rank/branch/unit patches on them, should remove those out of respect for the men and women who have served. These types of players should be POLITELY reminded that it's very frowned upon to wear something you personally haven't earned. If someone is going to be an all out asshole to a little kid wearing his dad's or grampa's bdus, that person can leave and not come back. There's no excuse for being a belligerent dick to someone for a simple mistake.
Now, what I do take issue with and will warrant a change or leave conversation are these players who INTENTIONALLY wear rank/unit/tabs and try to be a hard ass.
There was a player a few games ago who was all decked out in his Ranger gear ( including tabs and rank) trying to play off like he was a bad ass. Before I could say something, he must have over heard former service members saying something about it, and left.
If you're a younger player and all you have access to is a family members bdu with rank, you're not going to get picked on or harassed. Someone may say something, politely explain the situation, and everything should be cool. If they continue to give you a hard time, come see one of the hosts/refs.
If it's surplus gear you just bought, come see one of us, we can help you take it off without ruining anything.
If you show up wearing a ranger tab and SSGT rank, I guarantee, you're going to have a bad day.