In March 2013 Brown joined Nixon Peabody, a company which provides legal and lobbying services. Nixon Peabody reported that Brown would be working with the financial services and commercial real estate industries. In April 2014 Brown left the company. This work later received media attention when Lawrence Lessig with the Mayday PAC called Brown a lobbyist during the 2014 Senate election campaign. Brown's campaign denied the claim and said that Lessig had breached the honor code of Harvard University in making it.