Some people get upset about this and some people let those people know that it's not a big deal because it's only one day out of the year.
This discussion is repeated on every joke submission.
I was submitting blog posts on technologies and startups and used a bit of a sense of humor as well, but the whole blog is blocked now and appears the entries are in "the phantom zone" or whatever.
I don't really think that Hacker News has a sense of humor, and if it does, a majority of the people hate me for some odd reason to flag my submissions, while upvoting on other submissions that repost what I submitted but made the front page?