Yes, a break-away if it's on a cam-lock, as that is law in my state on a lock of that kind. What kind of break-away do I use? An s-hook Made by Hal Sullivan. I have 3 different set-ups. So I'm still trying to improve it to make it fool proof. As if.
But I do foot snare a number of foxes and coyotes each year, and yes, it's on purpose. Most of my set-up include a Slim ( for low visability) or Gregerson lock on a (3/32 swagged down to a) 5/64 stainless 7x7 cable. (It's the same cable used in artifical limbs. Only a handful of snaremen know this) The snare is tripple swiveled, which is where the set-up varies. Some also have stop-shocks on them. Still experimenting on that one. I use a snare support that I've designed which is, in my opinion, the best one out there. All my stuff is camo painted to blend in with the enviroment. A lot can be shown easier than explained over a type writer.