Hi Annker and tintin
Are you sure that all the poo is hog poo? Is there any chance that cats or a dog could be sneaking in as well. Spraying up the wall sounds more cat like. I keep finding dog poo on a part of my garden which is easily accessible to outside – not been a problem in that area before. It seems as well as all the lovely things people are doing for each other, a minority are being anti-social.
I think time will tell if these changes in behaviour of humans will benefit or be bad for the hogs. There are pros and cons. i.e. if the restrictions are lifted and more traffic is around, just when any hoglets are beginning to go out and about that could undo any good that was done previously.