Silicon Valley ad business gets a lift from the feds: opinion

(FILES) In this file photo taken on March 23, 2018 This photo illustration taken on March 23, 2018 shows Facebook logos on a computer screen in Beijing. Facebook announced on May 24, 2018 it will apply to its users accross the world the EU's General Data Protection Regulation (GDPR). The GDPR, which comes into effect on May 25, 2018, aims to give users more control over how their personal information is stored and used online, with big fines for firms that break the rules. / AFP PHOTO / NICOLAS ASFOURI

Somewhere in Silicon Valley, a bunch of Facebook Inc and Google ad salespeople must be rubbing their hands with glee. 

The reason? Federal prosecutors in Manhattan have opened an investigation into the way advertising agencies buy media space, according to the Wall Street Journal. Shares in WPP Plc, Omnicom Group Inc, Publicis Groupe SA and Interpublic Group all fell on Thursday.