The Chicago-based firm is following in the footsteps of several other major law firms seeking to cut a slice from the data protection pie. Baltimore-founded firm Venable and Washington DC-based Covington & Burling have both expanded their data privacy capabilities in recent times.

Confidential information

Ms Callahan - appointed to her previous post by President Barack Obama in 2009 - will focus on information governance and security, including advising companies on national security-related issues that arise when defence contractors and the government share confidential information.

The lawyer, a former partner at law firm Hogan Lovells, told the Washington Post she thought the market  was ripe for such a move, adding that there privacy practices were growing across the US. 'People are understanding this isn’t just about, “Can I send an e-mail?” It’s more about, “What can do with information, and how do I move from legacy databases to the cloud?”'