Betteridge's Law: "Any headline which ends in a question mark can be answered by the word no." [1]
[1] http://en.wikipedia.org/wiki/Betteridge's_law_of_headlines
This "law" fails many tabloid-style headlines, and other obvious cases.
eg.
"Where's the money?" (headline about corruption involving tax-payer money)
"Is Betteridge's Law of headlines ever worth invoking?"
"Manchester United: Will they ever return to form?"
Betteridge's Law: "Any headline which ends in a question mark can be answered by the word no." [1]
[1] http://en.wikipedia.org/wiki/Betteridge's_law_of_headlines