Williams & Connolly LLP represents government contractors, other corporations, individuals and whistleblowers in complex civil, criminal and regulatory actions brought by or against the federal government. The firm successfully represented a government contractor regarding its personnel at the Abu Ghraib prison. In a case of first impression, the court granted summary judgment for Williams & Connolly's client, finding it immune from suit because its actions were under the day-to-day control of the military. The firm also obtained a jury verdict in favor of another defense contractor in a trial over its provision of security services in Iraq. Also, a prominent government contractor retained the firm to defend it in litigation arising out of Boston's "Big Dig" road construction project. The firm represents a number of federal employees and government contractors in criminal matters, and in disputes related to security clearances, including one Air Force major in a procurement case and a Marine lawyer in a Special Selection Board matter.

Recently, the firm completed its representation of a whistleblower who had accused billionaire investor Mario Gabelli and certain Gabelli affiliates of violating the False Claims Act by using sham companies to acquire wireless telecommunications licenses under a Federal Communications Commission program intended to benefit small businesses. The defendants settled the case for $130 million, plus the firm's fees and expenses. The firm's other experience in qui tam litigation includes defense of significant claims in the pharmaceutical, pharmacy benefits manager, Medicare processing intermediary, military, and other industries.

The firm's lawyers have experience in all aspects of criminal proceedings arising out of federal programs, and in the traditional areas of bid protests and contract disputes. The firm has also handled claims for damage to property brought under the "takings" clause of the Constitution in areas as diverse as aircraft noise, and regulation of the savings and loan industry. The firm's practice is informed by the vast experience gained by its lawyers from serving in high-level positions throughout the government - the General Counsel of the Department of Defense, the Secretary and Undersecretary of the Air Force, Chief Counsel of the Food and Drug Administration, Chief of the Criminal Tax Division of the Department of Justice, Counselor to the Secretary of State, Assistant to the Chief Counsel for the Internal Revenue Service, and as prosecutors and in other trial positions in the Department of Justice. Several lawyers are serving and have served on the Defense Science Board and other federal advisory committees.