This happened to a friend of mine. She is a master gardener and had an absolutely beautiful perennial garden in front. New neighbors moved in with a travelling circus of animals. Wonderful people - would give you the shirt of their backs, but they had never lived in a development before. They had always lived on large acreages and farms in the midwest. So, they had no clue on how to be a good neighbor in tight quarters.
They had five cats that they let roam night and day. Three were promptly eaten by the coyotes that live on the outskirts of the neighborhood. The HOA did a study and found that about 50% of the free ranging cats in the neighborhood eventually are dinner for the numerous wild animals - coyotes, eagles, owls, hawks, mountain lions, etc. So, animal loving residents are always concerned when seeing cats run loose.
The remaining two cats decided that the nicely tilled bed of rare and expensive perennials was the ultimate kitty litter box.
My friend approached the new neighbors several times, reminding them of the dangers of leaving the cats loose and letting them know that she would not tolerate any more cat poop in her gardens.
One day, she opens her front door to the most horrific smell. The neighbors, in good faith, had emptied 20+ boxes of moth balls into her garden - saying it was a known deterrent for cats. Well, it did deter the cats, but it also deterred humans wanting to walk up the sidewalk to the front door.
Sadly, after several warnings to the owners, my friend ended up taking the cats to the local no-kill shelter because of her concern that they would also become food for the local wildlife and the mess they were making of her garden.
After having to bail the kitties out of kitty jail, the neighbors never let them run loose again.