Of those on the list, only Ohr is still employed in government service, but maintaining a security clearance is useful for finding documents if any of them are called to testify before special counsel Robert Mueller investigation.
"Let him write his report".
Brennan also told Maddow that he was considering his legal options after Trump pulled the security clearance "to prevent this type of abuse by Donald Trump in the future". The opposition research firm hired former British spy Christopher Steele during the 2016 presidential campaign to compile the dossier.
In August 2016, just two days after Brennan briefed Senator Harry Reid and other members on Russian interference in the election, the Nevada senator wrote a letter to then-FBI director James Comey, calling the FBI to investigate Trump's campaign.
Trump lashed out again at Special Counsel Robert Mueller, who is leading an investigation into possible collusion between his 2016 campaign and Moscow.
"I will be introducing an amendment next week to block the President from punishing and intimidating his critics by arbitrarily revoking security clearances", Warner tweeted. "I call it the rigged witch hunt", Trump said of the Russian Federation probe. "You're trusted with that information", Webb said of officials keeping their clearances.
Ohr works in the Justice Department's criminal division, and was in contact with former British spy Christopher Steele, who compiled a dossier of allegations of possible collusion between Trump's camp and Russian Federation during the 2016 presidential campaign.
"I don't trust many of those people on that list", he said.
The White House denied that revoking the clearance was a retaliatory move, saying it was done in response to Brennan's "lying" and "increasingly frenzied commentary".
The only question remaining is whether the collusion amounts to a "constituted criminally liable conspiracy", Mr Brennan wrote.
The piece, posted on the New York Times website, came a day after Trump announced he was stripping the security clearance of Brennan, who led the Central Intelligence Agency during most of President Barack Obama's second term and has emerged as one of Trump's fiercest critics. Bottom row from left: former Federal Bureau of Investigation deputy assistant director Peter Strzok, former Federal Bureau of Investigation lawyer Lisa Page, former deputy attorney general Sally Yates and former National Intelligence Director James Clapper.
Former CIA directors and other top national security officials are typically allowed to keep their clearances, at least for some period.