When the Knicks secured a spot in this year's NBA playoffs, I felt the need to give their Wikipedia entry a little update. Unfortunately, Wikipedia didn't like what I had to say. I updated the information about their current season and added that they were scheduled to play the Boston Celtics in the first round of the playoffs.
It stayed up there for a while, but when I checked the next day, it was gone (but not forgotten). I think it's probably harder to make an edit on such a popular Wikipedia entry, than a less popular one. If I had made an edit about my high school or my hometown, I believe I would have had a lot more success.