Didn't we all learn as kids the maxim, “people who live in glass houses shouldn't throw stones?” It's one of those little lessons taught to children, but like so many such maxims, it makes a lot of sense
When you set yourself up as an arbiter of what is true and just, you've just taken on a huge responsibility. And it doesn't take much for you to get knocked off your pedestal. Just getting the facts right is tough enough, but to be discovered to be engaging in fraud or other nefarious activities disqualifies you from the role you have tried to assume.
More on what happened to this internet “fact checker” on page two.