Sports data would be pretty easy to watermark - a fictional athlete here, a score for a game never played there, etc. none of it would ever be fully guaranteed

Sports data would be pretty easy to watermark - a fictional athlete here, a score for a game never played there, etc. none of it would ever be fully guaranteed to not cause someone a problem some day - “no dude, I swear the 1968 lakers played a pre-season game against the pistons and lost 123-98” - but there’s enough data that you could watermark it.