With tweetstorm, Trump may have exercised exclusive declassification authority

In tweeting accusations that President Barack Obama ordered surveillance of his campaign, President Donald Trump possibly made public the existence of top decret wiretaps - a move that would be a federal crime if performed by anyone other than the commander in chief.

Trump's stunning allegation came in an early morning tweetstorm, in which he wrote in part: "Terrible! Just found out that Obama had my 'wires tapped' in Trump Tower just before the victory."

Because the sitting president offered no evidence to back up his claim, it wasn't clear whether the tweet - which was followed by four others taking on his predecessor, including one misspelling the word "tap" - was based on classified knowledge he received in his capacity as president, or on an article posted yesterday to the conservative Breitbart website.

It also isn't known whether such federal wiretaps existed.

If - through his tweets - Trump revealed secret government information about surveillance, he exercised an exclusive privilege afforded only to the president as the ultimate declassification authority.

If any other government employee had singlehandedly made such revelations they could see prison time for potentially damaging U.S. national security, a former official with intimate knowledge of the government secrecy policies told ABC News.

"It's an extremely serious offense," ABC News contributor Matt Olsen, who is a former director of the National Counterterrorism Center and a former FBI counsel, explained.

"Anyone who would reveal the existence of a wiretap would violate federal law," he said. "It is against federal law to disclose the existence of a wiretap, whether that wiretap is for criminal purposes or intelligence purposes."

Wiretaps regarding foreign espionage and terrorism fall under the Foreign Intelligence Surveillance Act of 1978, issued by a secret court which meets in a secure courtroom shielded from public view or eavesdropping. Trump campaign aides have fallen under FBI scrutiny because of their repeated contacts with people alleged to be tied to Russian intelligence agencies, which the Trump associates may not even have been aware of.

The White House has so far offered no clarification on whether the president was citing sensitive, nonpublic information or it was prompted by a loose reading of the Breitbart article - itself based on a segment from conspiracy-loving radio host Mark Levin.

In a recent program, a clip for which was posted on Facebook on Feb. 16, Levin rhetorically asked, "How many of Trump's people were eavesdropped on, how many had their conversations intercepted, recorded, transcribed? Because this ladies and gentlemen is the big scandal."

Regardless of what prompted the rancorous tweets, a spokesman for the former president denied any wiretaps were ordered by then-President Barack Obama.

"Neither President Obama nor any White House official ever ordered surveillance on any U.S. citizen," Obama spokesman Kevin Lewis said. "Any suggestion otherwise is simply false."

The Obama administration's deputy national security adviser, Ben Rhodes, slammed Trump's accusations, writing on Twitter, "No President can order a wiretap. Those restrictions were put in place to protect citizens from people like you."

A senator from Trump's own party, along with U.S. intelligence officials, called the Twitter rant - which began just before 6:30 a.m. Eastern time on Saturday - a worrying display of Trump temperament.

"I am very worried. I'm very worried that our president is suggestion that the former president has done something illegal," Sen. Lindsey Graham, R-S.C., said.

Trump's tempestuous tweets served to keep the public's attention on Russia and contacts between the Russian ambassador and at least five Trump advisers.

It also comes one day after a Democratic member that he believed key wiretaps are, in fact, part of the investigation, although he has not seen them.

"There are transcripts that provide very helpful, very critical insights into whether or not Russian intelligence and senior Russian political leaders including Vladimir Putin were cooperating, were colluding with the trump campaign at the highest levels to influence the outcome of our election," Sen. Chris Coons, D-Del., said in an appearance on MSNBC.

ABC News' Randy Kreider, Cho Park, Alex Hosenball and Paul Blake contributed to this report.

Editor's note: An earlier version of this story misstated the airdate of Levin's program that was quoted. It has been updated to reflect that a clip from the program was posted to Facebook on Feb. 16.