We have lots of feral cats here in NH and MA. The liberals would choke on their cereal if you suggested shooting them. As mentioned above, the Humane Society has a program for feral cats where they catch them, give them their shots, and then turn them back loose.
Heck, we are being overrun with coyotes these days and they don't even want to shoot them! Just this week, an off duty cop and his 4 year old daughter were attacked in Wilmington MA. This is a residential area about 15 miles from Boston! Still, the MA liberals talk about trying to coexist with the coyotes. Last Summer there was a similar attack and they interviewed the homeowners who stated that this just meant that their backyard was the coyote's territory, and that they would just have to bring the kids in the house before dusk to keep them safe. They even claim that it is man's fault because suburbia is consuming the coyote's natural habitat. Of course, don't confuse them with the fact the coyotes were not natural to this area until the last 20-30 years. They have spread down from the far north, and now cover the whole northeast. It is the coyotes that are consuming our natural habitat because they have no natural predators.
So, the chance of getting such a law passed is slim to none, and the antis will use it to beat us over the head as bloody barbarians. So, I guess the best bet is "don't ask, don't tell". See any cats in the woods, don't ask where they came from and don't tell where you left them!