It's not personally a problem for us, but our tenant has complained about them. She actually said the neighbour had put lots of nails in the fence - he had put nails in the posts, but that was an exaggeration. The boundary is our responsibility, and based on our tenant's original description, I said I'd write and ask thr neighbour to remove them. However to my mind, these seem like a reasonable and safe deterrent.
Would I be within my rights to ask him to remove the 3 inch nails sticking out from the posts, if not the actual deterrent strips? I want to keep our tenant happy, buy I do sympathise with thr neighbour wanting to keep her cats out of his garden.