Well you probably couldn’t go after someone individually with that kind of information, realistically. Most consumer grade connections have dynamic IPs. So the IP of user posting to reddit isn’t actually uniquely identifying. Your ISP could match which customer had which IP at a specific point in time, but if point in time you’re tying the IP to is when a given user posted a discussion about pirating, that doesn’t actually correlate to actual pirate activity happening at that time.