I suppose its the ferreting season coming up - but I've recently heard of a handful of cases around the country where ferrets have gone missing. In each case, it wasn't just the ferrets that went, but various items of ferreting kit too. One poor old chap lost his favourite ferreting spade, which he'd had since he was a boy.
I don't suppose there's much an individual can do, other than take some obvious precautions - locking up the gear if possible, perhaps moving the hutch out of sight from casual visitors, and rigging up a security light or two to discourage thieves from snooping around.
...or maybe you could catch up a few of these and keep them around the place - skunks! Apparently there are some living wild in Britain, and this one was spotted near Kidderminster. If you're about to press 'play' be warned, the chap who found it was so surprised that he said some rather rude words. You might want to mute your speakers for the sake of any children present!