the fact that range finders are not prohibited is beside the point
a man was ranging his target, The President
why?
this is unnecessary unless knowing the distance to the target is important for some reason
I don't see crossbows on the list either
Man with crossbow spotted, no problem it's not prohibited
I don't see blowguns on the list
I could keep going
The fact that the SS failed to prohibit a common shooter's tool is irrelevant
Why did they not follow up when they saw a man ranging the President