Updated: Feb 9, 2020
VIEW VIDEO AT THIS LINK: https://youtu.be/ed7k5OFz9mg
In response to a Politico article erroneously accusing Rand Paul of using the final deliberations of Trump's impeachment trial to name the alleged whistleblower on February 4, John Brennan wrote:
Rand Paul is beneath contempt. He typifies the worst of @realDonaldTrump’s craven enablers. Any Senator excusing this dangerous behavior makes a mockery of public service. History will revile all of you.  So, Rand Paul gave an epic response:
Do you want to know what’s a mockery of public service, John? Killing 500 people outside of any judicial system. Drone strikes on American citizens. Approving British spies to present a dossier of lies paid for by Hillary. Lying to Congress. Your shame alone should shut you up. 
Is Rand Paul implying the Disposition Matrix program? At Wikipedia you can find this:
The Disposition Matrix, informally known as a kill list, is a database of information for tracking, capturing, "rendering", or killing suspected enemies of the United States. Developed by the Obama administration beginning in 2010, it goes beyond existing kill lists and is intended to become a permanent fixture of U.S. policy.
The process determining criteria for killing is not public and was heavily shaped by National Counterterrorism Director and former Central Intelligence Agency (CIA) Director John O. Brennan.
Though White House, National Counterterrorism Center (NCTC), and CIA spokespeople have declined to comment on the database, officials have stated privately that kill lists will expand "for at least another decade", if not indefinitely. One official stated, "it's a necessary part of what we do". Paul R. Pillar, the former deputy director of the CIA's counterterrorism center, has stated, "We are looking at something that is potentially indefinite".
The database's existence was revealed in a three-part series published by The Washington Post newspaper. According to The New York Times, Brennan was the "principal coordinator" of U.S. kill lists. Former Obama administration counter-terrorism official Daniel Benjamin has stated that Brennan "probably had more power and influence than anyone in a comparable position in the last 20 years".
The Disposition Matrix database catalogs biographies, locations, associates, and affiliations of suspects. It also catalogs strategies for finding, capturing, or killing suspects, or subjecting them to extraordinary rendition.
The criteria and decisions determining who may be targeted for killing are developed in large part by John Brennan, who "wields enormous power in shaping decisions on 'kill' lists and the allocation of armed drones."
As reported previously, United States citizens may be listed as targets for killing in the database. This is scary stuff considering John Brennen made the ultimate decision on who was and who was not a threat based on his ethics. Ouch! Get this: Suspects are not formally charged with any crime or offered a trial in their own defense.
Obama administration lawyers have asserted that U.S. citizens said to pose an "imminent threat" against the United States may be killed without judicial process. The legal arguments of U.S. officials for this policy were leaked to NBC News in February 2013, in the form of briefing papers summarizing legal memos from October 2011.
Here’s another doozy: The Obama administration's drone program received approval from Republican Party presidential candidate Mitt Romney during the 2012 U.S. presidential elections.
Glenn Greenwald, Guardian Newspaper writer concludes that the Disposition Matrix has established "simultaneously a surveillance state and a secretive, unaccountable judicial body that analyzes who you are and then decrees what should be done with you, how you should be "disposed" of, beyond the reach of any minimal accountability or transparency".
Former counter-terrorism specialist and military intelligence officer Philip Giraldi has criticized the disposition matrix's "everyday" killing of targets with what he calls "little or no evidence", leaving the former White House "completely unaccountable. 
In 2018 Two ominous tweets, one written by former CIA Director John Brennan, the other by former United Nations Ambassador Samantha Power, openly threatened a sitting president — President Trump.
After the long-overdue firing of Andrew McCabe, President Trump tweeted to the American people that McCabe’s termination (and possible loss of pension) marks a “great day for the hard-working men and women of the FBI – A great day for Democracy.”
Trump added that “James Comey … made McCabe look like a choirboy. He knew all about the lies and corruption going on at the highest levels of the FBI!”
We now know that Comey leaked internal memos about his alleged conversations with Trump to the media through a surrogate, an act that many believe violated FBI rules, possibly even rules surrounding classified information. Moreover, Comey’s greasy fingerprints appear to be all over the discredited Russian dossier and the FISA warrants obtained using the dossier to spy on surrogates of the Trump campaign.
“When the full extent of your venality, moral turpitude, and political corruption becomes known, you will take your rightful place as a disgraced demagogue in the dustbin of history,” Brennan blasted to Trump on Twitter. “You may scapegoat Andy McCabe, but you will not destroy America…America will triumph over you.”
The question is what did Brennan know at that time? And where did he get the information that allowed him to confidently threaten a sitting president with “disgrace” and a place “in the dustbin of history?”
Brennan’s tweet took on an even more ominous tone after Power later tag-teamed it with this tweet: “Not a good idea to piss off John Brennan,” she warned, with a link to Brennan’s tweet threatening Trump.
Again, Brennan is the former head of the CIA, a man with incalculable residual power through various contacts, not just within the bureaucratic Deep State, but within the wide world of international spycraft.
The very idea that a Brennan and Power, two former Cabinet-level officials in the Obama administration, were publicly hurling not-so-veiled threats at a sitting American president, should have been taken seriously.
Remember when Senate Minority Leader Chuck Schumer, seemed to gloat over the fact that the intelligence community has “six ways from Sunday at getting back at you” — meaning Trump?
This is the rhetoric of a state-run by an un-elected secret police force, not a representative democracy where the intelligence community is supposed to answer to the people through our elected representatives.
We badly need a special counsel to investigate Brennan and his threats. The Secret Service might also want to get itself involved. Is this what Rand Paul is eluding to in his tweetstorm to John Brennan?  President Trump surely seemed resolved in the Prayer Breakfast and Press Release yesterday. Perhaps it’s time; even past the time to arrest these criminal scoundrels.