This article suggests that the President's "information" that Obama tapped his phones may be from a Breitbart article.
I think it's more likely that one of his aides used their new security clearance to find out that Trump Tower was subject to a FISA-authorized wiretap, and then told the President what they found. In which case, Trump is either revealing classified information in his tweets, or declassifying the information by deciding to release it to the public. But if there was a FISA warrant, that means a federal judge found probable cause for a warrant. Which means that if the President actually does know what he is talking about when he accuses the Obama administration of a tap on his phones (as opposed to echoing some Breitbart piece that may or may not have any credibility), then this is a signal that there really is something to be investigated about Trump.
I think it's more likely that one of his aides used their new security clearance to find out that Trump Tower was subject to a FISA-authorized wiretap, and then told the President what they found. In which case, Trump is either revealing classified information in his tweets, or declassifying the information by deciding to release it to the public. But if there was a FISA warrant, that means a federal judge found probable cause for a warrant. Which means that if the President actually does know what he is talking about when he accuses the Obama administration of a tap on his phones (as opposed to echoing some Breitbart piece that may or may not have any credibility), then this is a signal that there really is something to be investigated about Trump.