President Trump slammed the media for protecting their confidential sources during his speech at CPAC on Friday morning. "They have no sources. They just make them up when there are none," Trump told the audience.

As evidence, Trump referred to a nine-source story written by The Washington Post that reported that former National Security Adviser Michael Flynn had discussed sanctions in phone calls with the Russian ambassador before President Trump's inauguration. Following the report, the White House confirmed Flynn's phone calls and his denial of them to Vice President Mike Pence, which resulted in his resignation:

This is bizarre. Trump says WaPo made up sources on the Flynn story, which resulted in WH confirming story and firing Flynn over it. — Benjy Sarlin (@BenjySarlin) February 24, 2017

"I know who they talked to," Trump told the audience. "There were no nine people."

Trump went on to say that journalists should not use anonymous sources in their reporting: "They shouldn't be allowed to use sources unless they use a name," Trump said. "Let their name be put out there ... Let them say it to my face."

Trump at CPAC: I'm only against the "fake news media," they shouldn't be allowed to use unnamed sources https://t.co/JXFn9sZPaB — Anderson Cooper 360° (@AC360) February 24, 2017

Journalists use anonymous sources to allow people with knowledge of certain situations to speak freely on topics that they might not otherwise be able to discuss. "Anonymous sources are sometimes the only key to unlocking that big story, throwing back the curtain on corruption, fulfilling the journalistic missions of watchdog on the government and informant to the citizens," the Society of Professional Journalists writes.

Even many Republicans agree with these source protections. When he was an Indiana representative, Vice President Mike Pence fought to protect journalists and their sources. Forcing reporters to reveal their anonymous sources, he argued, "chills reporting of the news and restricts the free flow of information to the public." Jeva Lange