Re: Neighbours.
Razor wire. Broken glass set in cement.
Yes, I remember the latter when ah wer a lad, on the wall surrounding the local cricket pitch, for example. Both illegal now, I should imagine, unless accompanied with illuminated warning signs, safety barriers and first-aid boxes fitted to the wall!
When we first moved into our house, it wasn't long before we had some 'visitors' climbing over our garage to get in. They ran away to a neighbouring property when the police came.
I wasn't entirely happy with that, of course, so added some barbed wire (didn't have any new-fangled razor wire) in appropriate places.
I didn't leave it long, though... not when it became apparent that criminals have more rights than home owners. So I reluctantly disposed of it.
Fortunately, we haven't had any more such trouble since - touch wood.
Not since I bought my double-barrelled shotgun anyway.
(Only joking!)