With over 170 episodes, it's understandable that some fans haven't seen all the episodes of Seinfeld no matter how many times they've been syndicated since their original air date. If you've never seen "The Puerto Rican Day" though, you might have missed it due to censorship. In fact, due to complaints about negative portrayals of Puerto Ricans and a burning Puerto Rican flag, the episode was banned completely between its original air date in 1999 and 2002. Even now though, some stations who syndicate the show won't touch it.
And that Seinfeld episode is only one of 27 episodes from popular TV shows that were banned temporarily for one reason or another. Perhaps the strangest of all was the Peppa Pig episode that shows kids that spiders are our friends. It was banned in Australia because the deadly spiders there are most certainly not your friend.