anonymous speech
This incident demonstrates why revealing too much information in a public forum can be dangerous: the GOP McCarthyites may accuse you of sedition and confiscate your PC. (The VA nurse in question, who had written a critical letter to a local newspaper, was cleared with help from the ACLU.)
It also demonstrates why blogging anonymously is sometimes a good idea.
(Thanks to Matthew Yglesias at TPM Cafe for the tip.)