When someone follows you or otherwise does something you might think is annoying/rude/racist (but isn’t threatening to your physical safety), don’t walk up to them, punch them in the face, mount them, and beat the crap out of them.
If you are someone who commonly does this when people annoy you, you should stop doing so as soon as possible. And if you are someone who finds this behavior to be obviously over the top and grounds for legitimate (and even lethal) self-defense, welcome to the 99%: you’re in very little danger.
There’s a reason neighborhood watchmen aren’t shooting people every single day. It’s because most people they follow, give dirty looks to, and otherwise harass don’t walk up and assault them.