do you have to actually pay anything? in the us you also get a scare letter from your ISP but nothing happens if you ignore it and continue
Yeah, because it's lawyers working for the rightholders sending them, not ISPs. You can sometimes get out, but only by replying properly, ignoring then will end in court.
That’s not true in some places like Germany. Just a few seconds of uploading a somewhat popular movie or porn without a VPN will get you a C&D + fees letter.