It's fine to let your cats roam in farming areas, but in urban areas it is just not right to let cats run free as there are too many of them, there is no doubt that they are reducing the number of song birds in our communities. I am also bothered by neighbors cats in my yard, If we see them out there, we try and scare the crap out of them by yelling, running after them, throwing rocks, not to hit them of course, during the summer the hose if I can sneak out and turn it on.