I believe part of my success against some predators like foxes, raccoons, and coyotes has to do with NOT trapping and killing them.
Good points!
I am no veteran when it comes to dealing with predators, but I know most of the land predators are quite territorial, (even heard some coons fighting it out this morning).
For example: say a fox or a raccoon comes upon a chicken coop in it's territory for the first time.
Of course it will test the coop to the limit, if it can't get in no matter how hard it tries, it will move off and try again later. When it tries later and can't get in (assuming you keep your coop strong) it will eventually give up completely, maybe giving the coop a glance or check-over every now and then. My point is instead of killing the fox/coon and having a new one move in time after time to test your chicken coop, keep that ol' frustrated predator around. It doesn't get rid of the predator problem obviously, but you won't have to deal with him or her coming up and testing it that much (and that way it usually won't take advantage of anything broken as much after it has given up.)
I'm not saying it is bad to get rid of predators. If the predator in the area becomes bolder and starts taking birds in the day (if you free range your feathered friends). Then I say shoot them or trap them, better to be rid of a bolder predator than keep it around instead of one that is shy.
Just my two cents.