As a recipient of such a letter, I can tell you that the amount you torrent isn't really the problem, it's about the specific content. It works like this: copyright lawyer company monitors torrent trackers, then goes to a copyright-friendly court/judge with a list of IP-addresses that were up/downloading the copyrighted content of the media company they represent, they get some kind of court order from the judge to pressure ISPs to give up information about users behind the IP-addresses.

The letter I got was from Universal's lawyers and amongst the various movies I downloaded, all they cared about was the new "Dune". The letter was detailed with lots of lecturing, legalese, timestamps, info hash of the content and at the end they ask for 400€ or else they might escalate in court. I didn't want to pay or risk it, so there is another lawyer who specializes in these letters who you can pay 200€ to take care of things.

I saw the whole thing as a lesson learned that yes, I am being surveilled and no, my ISP is not my friend, but an adversary who keeps logs and doesn't care much about protecting my privacy. From now on I do most of my browsing and all torrenting via Mullvad VPN, paid for with Monero.

Once is enough. They just need to catch your IP once. Like roxil said, they are looking for specific content usually. Mostly new releases. I guess this looks better in front of a judge too, instead of going to court over watching a blurry episode from a show from the 80s that has been rerun on free TV hundreds of itmes.

I do, yes.

But I just wanted to point this out to those that don't know.