I have gotten a few notice alerts over the year and it seems to depend on what you are downloading not how much or how often. If it is a popular TV show or movie they are more likely to get you versus an old movie from the 80s. Given how easy it is to get a VPN and how cheap it is I would not even chance it.
It's against the law, so there is chance you eventually get caught, if your seeding copyrighted material. I do not know anybody who was caught, but if your naive, you might get in trouble.