In 1942 the school placed an anonymous letter in the Daily Telegraph to recruit people who were crossword puzzle experts.

FORBES: I've got a secret

That all went up in smoke after an anonymous letter, presumably from a disgruntled former employee, was sent to a police department in Long Island.

FORBES: Inside Dope

It was revealed through a freedom of information request to a former councillor who said he had an anonymous letter revealing that some staff had a "buy out".

BBC: The Unison protest

That same month, an anonymous letter arrived at the S.E.

NEWYORKER: A Dirty Business

Half the time, cheating partners are found out through indiscreet mobile phone text messages, one in five are betrayed by emails, and only one out of 10 are given away by the traditional, anonymous letter.

FORBES: Can Adultery Cure the Winter Blues?

An anonymous poison pen letter was sent to Raymond and Sacha Hubbard, who own a garden centre, but the pair have resolved to keep their topiary effigy.

BBC: 10 stories that could be April Fools pranks but aren't

An open letter, purporting to be from Anonymous, accused the church of bigotry and fanaticism.

BBC: Westboro Baptist Church targeted by Anonymous

Last week an anonymous group of "netizens" posted an open letter on Chinese blogs and forums.

CNN: China delays Green Dam Internet filter

The letter says there are no legal reasons for not sharing anonymous information, and asks for any "good reasons why it cannot be done" in areas which have failed to put systems in place.

BBC: Many hospitals not sharing crime data, audit shows

She agreed to testify only after Libby sent her a letter releasing her from the promise to protect him as an anonymous source.

NPR: Reporter Miller Returns to Stand at Libby Trial