Donald Trump released a barrage of outraged tweets on Saturday morning, accusing Obama of tapping his phone before the election and calling him a "bad (or sick) guy". In fact, current evidence suggests intelligence officials looked at emails and other documents from a computer server; there's no indication of eavesdropping.
Trump's tweetstorm seems to have been sparked by a recent Breitbart story, which rounded out claims by radio host Mark Levin that former President Barack Obama monitored Trump's communications in the lead up to election night. The article cites a story on Heat Street, which reported that the FBI requested a warrant to investigate the Trump campaign's ties to Russia in June - under the Foreign Intelligence Security Act (FISA) - but was denied. However, the agency later pointed to evidence of a private server in Trump Tower communicating with Russian banks, and secured a FISA warrant in October.
Heat Street reported the second warrant was drawn more narrowly, leaving out Trump's name and targeting the server in question. The court granted permission "to look at the full content of emails and other related documents that may concern US persons", according to Heat Street's two sources, who have links to the counter-intelligence community. Although Trump isn't named, the sources believe the warrant covered any Americans connected to the investigation, a group that included Trump and at least three of his campaign officials and media surrogates.
The accusation of phone-tapping seems to be based on an interview with former National Security Agency (NSA) offical William Binney, broadcast on Aaron Klein Talk Radio. The "architect of the NSA's surveillance program", now a whistleblower, was asked whether he thought the NSA is tapping Trump's phone. Binney replied, “Absolutely. How did they get the phone call between the president and the president of Australia? Or the one that he made with Mexico? Those are not targeted foreigners.”
Binney also suggested the NSA may have leaked the details of national security adviser Michael Flynn's phone calls with the Russian ambassador, leading to his resignation after he misled Vice-President Mike Pence about their contents.
Trump's claim that his phone was tapped looks to be based on pure speculation. It's also unclear whether the FBI read his or his advisers' emails or monitored their communications, as the warrant was granted to investigate the suspicious server. This may just be the president's latest attempt to shift attention away from his administration's ties to Russia.
Attorney General Jeff Sessions is under fire for failing to disclose his two meetings with the Russian ambassador, when he was asked under oath about the Trump campaign's contact with the Russian government. The president has frantically called for investigations into top Democrats Chuck Schumer and Nancy Pelosi, after pictures surfaced of their past meetings with Russian officials, but they never lied under oath about them.
In short, Trump has levelled serious charges against a former US president, based on anonymous sources (which he despises) and speculation. Just another weekend in Trump's world.