If it's a one-off story being told in a comment, I don't care. If it's one where it becomes obvious that it's fake while reading it (e.g. the jumper cables guy, or the Hell in a Cell guy), that's great.
When it's problematic to me is when it's posted as a thread purporting to be asking for advice about a topic, or one intended to be controversial. I don't want to waste my time writing a thought-out response to a post to help someone, only to find that it was fake all along, or debating solutions to a non-existent problem with people.