OLATHE, Kan.—Soon after Jim Hildenbrand arrived in Avignon Villa Homes, a community for older adults in a Kansas City suburb, the homeowner association disputed the placement of his satellite dish. It cited him for parking cars in his driveway overnight and placing a St. Francis statue in a flower bed. He was later written up for a dead cat in a window well—which Mr. Hildenbrand suspects was planted by a neighborhood enemy.

Things went downhill from there.

After...