Updated

Kentucky GOP Sen. Rand Paul -- the libertarian who blocked a Senate vote for nearly 14 hours over drone strikes -- says the NSA spying has "gone too far" and is speculating about whether the agency has tapped into President Obama's cellphone.

Paul's comments follow the most-recent revelations about the NSA's post 9-11 data collecting -- that German Chancellor Angela Merkel was a victim and the agency purportedly had access to the servers of Internet giants Yahoo! and Google.

The senator made the comments during an interview this weekend with Bloomberg's “Political Capital with Al Hunt” and acknowledged being "a bit" fastidious about the president's cellphone because it is almost certainly encrypted. But he was using that extreme hypothetical situation to point out the NSA gets its authorization from the secretive Foreign Intelligence Surveillance Act court so most anything is possible.

"Are they tapping the president's phone, also?" asked Paul on the show. "He's got a cellphone. … And I say that a bit facetiously, but at the same time, the warrants that are coming out of the FISA court are so expansive and without limit and non-specific that they apply to all cellphones. So conceivably the NSA could be spying on the president's phone."

This is not the first time Paul -- a first-term senator and potential 2016 presidential candidate -- has sharply criticized the Obama administration about what he perceives as too-secretive operations.

In March, he staged a filibuster-like speech on the Senate floor in protest of Obama not clearly telling Americans whether they could be hit by a drone strike on U.S. soil.

The president weeks later released classified information showing four U.S. citizens had been killed by drones on foreign soil and said, “I do not believe it would be constitutional for the government to target and kill any U.S. citizen -- with a drone, or a shotgun -- without due process. Nor should any president deploy armed drones over U.S. soil."

Paul told Bloomberg the definition of overreach is "everything the NSA has been doing over the last several years” and said the agency's secret surveillance efforts needs to be “debated, and discussed” openly before the Supreme Court.

"We've gone too far," he said. "The president likes to say there's a balance between liberty and privacy … and government. We've gone overboard. … It totally goes against everything our country stands for to have a secret court … meets in secret."

He also said that Obama not knowing about NSA surveillance on U.S. allies is "hard to believe."