MOSCOW, May 23 (RAPSI) – Members of the German parliamentary commission, which is investigating the US National Security Agency’s (NSA) questionable activity, want the heads of US high-tech companies, including Apple, Facebook, Twitter and Google, to testify to the Bundestag, writes Frankfurter Allgemeine Zeitung.

In March, the German parliament’s lower house voted to investigate the NSA’s operations in Germany. According to the documents leaked by NSA whistleblower Edward Snowden, the NSA monitored the telephone conversations of Chancellor Angela Merkel and other members of the German political and economic elite.

The MPs want to determine if clients of the US tech giants were safely protected from NSA spying. NSA General Counsel Rajesh De said in March that Yahoo, Apple, Google, Microsoft, Facebook and AOL knew that the agency used the internet collection program known as Prism to harvest all communications content and associated metadata under a 2008 surveillance law.

The commission will discuss the initiative of the Bundestag deputies at its meeting on Thursday. They also want to hear testimony from some of the NSA’s employees, including Gen. Keith Alexander, who served as NSA director from 2005 to March 2014.

Die Welt writes that the MPs had sent summons to the hearing to incumbent Chancellor Merkel, former Chancellor Gerhard Schroeder, US journalist and lawyer Glenn Greenwald, who was the first to publish Snowden’s documents, and Edward Snowden.