yes, i should clarify that LA has a pretty effective no-kill cat rescue network (even sending rescues to other states for adoption), so most cats here are neutered, chipped, vaccinated, and tattooed when rescued and adopted out (e.g., my sweet little rescue cat). but there are also dedicated TNR volunteers who strictly neuter and release stray cats and employ the ear-clipping method for that reason (easier to see from distance).

ear-clipping isn't foolproof though, since many feral cats will not sit still long enough or let you get close enough for you to observe a clipped ear. that said, plenty of stray cats are relative docile and friendly, and totally adoptable by simply picking them up and taking them home (which is what one of my neighbors did).