The District of Columbia's Fraternal Order of Police recently filed a complaint against the District of Columbia concerning a FOIA request it made pursuant to the D.C. FOIA (which largely mirrors the federal FOIA).
D.C. then took the largely unprecedented and rare move of serving discovery on the plaintiff. After a motion for a protective order, D.C. backed down and withdrew its discovery request. However, as I've never heard of anything like this, I thought it was worthy of a blog post.
The parties are still quibbling about the discovery--as you can see from these filings with the court.