Your Hypothetical "Universal Ignore List"

It’s software to install a block on your OS or browser, not “real life.” How did you learn about people before the internet?

Just to answer your question: The Media. Radio, TV, Newspapers, Magazines and other sources I could pick and choose based on my expectations of finding interesting people and few, if any, dregs of society. If we want to go pre-internet, I wouldn’t have any problem with some way to keep from hearing or reading about people I had zero interest in.

I could name dozens of people that crept into my awareness that I would just as soon hadn’t. All the way back to childhood.