I'm genuinely curious about this because I've always seen all the fcc stickers and never bothered to think much beyond "oh nice that means it won't electroshock

I'm genuinely curious about this because I've always seen all the fcc stickers and never bothered to think much beyond "oh nice that means it won't electroshock me I guess?" I didn't realize they were about actual electromagnetic interference. So like, what's bad about that? For example, I life in an apartment with concrete walls, ceiling, and floor. Is there a risk I'll affect my neighbor's pacemaker with my extensive collection of electronics, probably many of which are poorly shielded? Is this affecting my network cables running hither thither in the apartment, or the switch plopped on top of a pile of cords with a raspberry pi sitting bare on top of it? My steam link downstairs? Is it causing cancer? Making my audio quality worse in my speakers? Basically, what should I be worried about, here?