I've never gotten a scary letter, and I've certainly torrented my fair share of stuff, both legal and otherwise.

The trick, I think, is to not use cable. I've had municipal fiber, Google fiber, DSL, and small local ISP (RJ45 hookup at the wall), and never once had an issue. The last one is probably annoyed at me because I tend to submit tickets and call them within a few minutes of my service going down (happens once/month or so). It's extra funny when they ask me to check my wifi settings on my router, and I tell them my router doesn't have wifi (it's a Mikrotik router, my AP is separate), and that my wifi is absolutely fine, it's the uplink that's busted (i.e. I can access all the stuff on my NAS).

I made a promise to myself that once I left the house, I'd never get cable. And that's a promise I've kept across multiple apartments and now my house. We're finally getting muni fiber, so I'm pretty excited.