Our security guys are great, they don't tolerate anything towards the nurses (or docs). No hassle about getting a doctor's order for restraints first either.
In triage, I sit in the "fishbowl", locked door to my left, bulletproof glass in front of me. Yes, you have to pick up the phone to talk to me! and if I call, security will go out the door first if someone runs in wanting help getting a patient out of the car.
And PD's pepper spray has been banned in the ER! Turned out the patient wasn't quite wide enough to catch all of it and my buddy got half of it.

yeah, she looked like that