Washington (CNN) Nobody outside the White House knows if Donald Trump is actually recording private conversations, as he teased in a tweet.

"James Comey better hope that there are no "tapes" of our conversations before he starts leaking to the press!" the President tweeted May 12 in a not-subtle warning to the deposed FBI Director.

James Comey better hope that there are no "tapes" of our conversations before he starts leaking to the press! — Donald J. Trump (@realDonaldTrump) May 12, 2017

This particular presidency being what it is, nobody's really sure if there's a new White House taping system or not. But for a president who was already dodging comparisons to Nixon for his firing of Comey -- Nixon fired the Watergate independent prosecutor Archibald Cox in a standoff over recordings in the White House -- teasing a taping system has spun the controversy in an entirely new and interesting direction.

We'll continue to track that. White House press secretary Sean Spicer wouldn't give any further information on it at Monday's press briefing.

NPR had a solid and relatively brief history of White House taping systems from FDR through Nixon , when presidents and their administrations wised up about the idea of recording their discussions.

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