I would be bloody furious! I had absolutely no idea humans would be as much trouble, if not more so, than 4-legged predators before we got chickens.
Our security:
Padlocks, the 4-directional ones, on each fence gate
Same on the shed doors
Two very loud Basset Hounds who will kick up enough fuss for me to grab a rifle or shotgun
Motion sensing light on the back of the house pointed at the coop door
A very complicated latch on the coop door
The master bedroom windows overlook both coops and there's a revolver in the nightstand (we don't have kids)
A duck flock who will scream and holler if anything disturbs them at night
So far, we've lost:
two rabbits to a neighborhood kid who snuck in and fed them eucalyptus from their mother's garden *sigh*
one rabbit to another neighborhood kid who stomped on it after he scratched her trying to get away. Also trespassing.
one lame duck to a Bald Eagle (I figure the Eagle was due)
one bantam chicken to a neighbor's cat (the bantams are now penned up)
one duck to a neighbor's loose dog