G'day David,
<snip/>
I just removed spoiler warnings from [[Agatha Christie]] ... and [[anagram]]. What on earth.
[[Anagram]]? What? <goes to look/>[0]
Oh, I see. In this case, I think a spoiler warning is justified[1]. If someone goes to read about /Harry Potter and the Chamber of Secrets/[2] and gets surprised by the anagram revelation, then TS to them; they shouldn't have been reading an encyclopaedia article about it. If, however, someone who may read /Harry Potter/ in the future innocently turns to read about anagrams, well, one can feel some sympathy if they don't want it spoiled.
Which is all the more reason, frankly, to remove the "... in popular culture" sections from articles unless they add something, which this one simply does not.
[0] Don't worry, it's my lunch break. Hey, I might remove some of them while I'm here. I wonder how many will get reverted because I can't log in. After all, if an IP removes anything, he must be a vandal.
[1] Assuming for the sake of argument, of course, that a spoiler warning is *ever* justified.
[2] Published in America as /Harry Potter and the Weird Hidden Room/.