The Canadian Radio-television and Telecommunications Commission (CRTC) used Canada's Anti-Spam law to take down a control and command server in Toronto for the Dorbot botnet.
The CRTC's press release is here. They worked with industry and government in many countries. Microsoft sent out a release with more details on the way Dorkbot works.
In addition to its anti-spam provisions, CASL sets rules for downloaded installable software, which ranges from benign smartphone apps and browser plugins to malicious botnets and password stealing malware. The CRTC investigation is ongoing so they haven't disclosed the details, but the authority to take down the C&C server appears to come from the prohibition against unauthorized downloads and installs. CAUCE congratulates the CRTC on this sophisticated and effective use of its new enforcement authority.