Porky's are very abundent in Maine and cause tremendous damage to trees. The big forestry companies like Scott, Boise Cascade, Warehauser etc absolutely hated them and asked hunters to shoot them on sight.
When I had coonhounds back in the 80's it was almost impossible not to have dogs get quilled up during the season. If I had a dollar for every quill I pulled from my coonhounds I could have retired 20 + years ago.
The Fisher which is twice the size of a Pine Martin is actually the Pork's greatest natural enemy.