I'm afraid to say that I'm worried that the more power you give guards to determine threats, the more they will harass folks. There is a bit of a ratcheting eff

I'm afraid to say that I'm worried that the more power you give guards to determine threats, the more they will harass folks. There is a bit of a ratcheting effect, no one will get in trouble for being too strict, but you're likely to get in trouble if you miss something, but there's also the human love of power in there. Give people power over a limited domain, and they just love to wield it.