The Office of the Chief Technology Officer wants you to watch your mouth.
Send an offensive word in an email to a city government employee, to be received at a "dc.gov" email address, and you'll be censored. The message will bounce back with a note that says, "Your recent message for [email address] titled [email subject] contains [...]

From Ward 7 Councilmember Yvette Alexander's Web site:

I mean, I appreciate the thought, but wouldn't that really cramp one's style?