As a frequent victim of "cat dumping," I feel the need to speak out.
On a recent day, after cleaning my front yard of feces due to "cat(s) dumping" in it, I removed Christmas decorations from my home. I then found a mess with my shoe I'd missed earlier. During summer months, "cat(s) dumping" in the flower beds creates an offensive stench, an embarrassment when guests arrive.
As a disabled person, I have a hard enough time performing household chores, and I've never had a cat owner offer to clean up after their free-roaming animal in my yard.
One way to create positive behavior change in people is to make it easy to do the right thing. I suggest making it easier to drop off a cat for free, than to abandon it somewhere. Pet stores come to mind as drop-off places, since it's inconvenient for most people to go to the animal shelter. Costs should be covered through mandatory cat licensing fees.
Any pet owner not responsible enough to care for and license a pet has no right to complain about forcing neighbors to take action to protect their rights against "cat dumping."