If anyone has read the book 1984, they'll remember one piece of the setting is that history is constantly being rewritten.  If I remember correctly, the main character's job was to actually perform these alterations of recorded history.
Anyway, lately every time I go to Wikipedia I think of 1984.  So many people, including myself, use Wikipedia to read up on virtually any subject.  I believe that a large majority of Wikipedia articles are factual, but I can help but wonder if what I am reading is actually true at all.  Just like in 1984, someone - anyone - could alter Wikipedia articles and basically alter human knowledge or change history in a sense.