G'day Sean,
So I remove the {{spoiler}} tag from (I wouldn't dare make this up) [[Three Little Pigs]]. I'm promptly reverted with the comment "unilateral enforcement of a matter still in dispute." Anyone who agrees (or disagrees) that I'm acting unilaterally is welcome to join the discussion. At [[Three Little Pigs]]. Really. I'm not kidding.
Nothing like [[Three Little Pigs]] (what a corker!), but amusing nonetheless: [[Baron Münchhausen]]. But wait! It's not just that a spoiler warning was considered necessary for this chap's life (or unbelievable retelling of same), but what precisely we were protected from reading.
For reasons unknown to my humble self, the article includes the table of contents, including the original ToC's introductory paragraphs, which explain what occurs in each chapter. Yes, the publisher isn't worried about spoiling your enjoyment with this, but some conscientious chap on Wikipedia wants to spare you where others callously refused.
(I wonder if he'd go to bookshops and paint over the blurbs with a texta, too, to prevent spoilers ...)