Cunningham... you've been served.

The New York Times:

[...]
Randy ''Duke'' Cunningham, R-Calif., told the House on Monday that he's been served with a document subpoena in Imperial County, Calif.
His announcement was read on the House floor by a congressional clerk as the House convened for the week.
[...]
It was filed by an attorney representing Imperial County in a lawsuit by a man who claims he was beaten in 2003 by a Bureau of Land Management ranger. The attorney, Michael R. Capizzi, said he filed the subpoena in early May to get written communications between the plaintiff and Cunningham, who made an inquiry on the plaintiff's behalf. The congressman has already complied with the subpoena.
Under House rules, members must alert the House when they receive a subpoena.
[...]

I also heard that there are 3 other subpoenas. I'm still looking for news stories to confirm that.