President Donald Trump has accused Barack Obama of tapping his phones at Trump Tower in a flurry of tweets early Saturday morning.

Trump tweeted that the former president had been spying on him in October, a month before his election victory.  'Terrible! Just found out that Obama had my 'wires tapped' in Trump Tower just before the victory. Nothing found. This is McCarthyism!'
McCarthyism, which the president used in his first tweet, is the practice of making accusations of subversion or treason without proper regard for evidence.
Trump started tweeting shortly after 3.30am ET and posed the question: 'Is it legal for a sitting President to be 'wire tapping' a race for president prior to an election?'
In another tweet Trump said it was a 'new low' for the former president and compared it to 'Nixon/Watergate'. Trump also linked Obama to Attorney General Jeff Sessions's meetings last year with Russia's US ambassador, Sergey Kislyak.
'The first meeting Jeff Sessions had with the Russian Amb was set up by the Obama Administration under education program for 100 Ambs,' he tweeted.
Trump's team has sought to push back over its connections to Russian officials by pointing out instances of Democrats meeting with Kislyak. The president did not provide any additional evidence to back up his claims. Obama has not responded to the accusations.
But he seemed to be referring to a Thursday evening radio show hosted by Mark Levin that claimed Obama executed a 'silent coup' of Trump via 'police state' tactics, according to far-right Breitbart News.

Levin suggested the former president should be the target of congressional investigation.

Just a day before the election last year, former Heat Street editor Louise Mensch reported that 'sources with links to the counter-intelligence community' confirmed that a Foreign Intelligence Surveillance Court (FISA) had granted a FISA court warrant in October to monitor activities in Trump tower.
On Wednesday, a New York Times report said White House officials took efforts in the closing days of the Obama administration to analyze and spread information about Russian election interference, driven by a concern that the material might get buried by Trump.
Intelligence agencies rushed to analyze raw intelligence material about Russia connections, going over months-old material as the extent and possible motives of what the agencies say is Russian election hacking emerged.
Officials made efforts to ask specific questions at intelligence briefings as a way to get the information into the record and be archived for examination later.
In January, American law enforcement and intelligence agencies examined intercepted communications and financial transactions as part of a broad investigation into possible links between Russian officials and associates of Trump, according to the Times.
The FBI led the investigations, aided by the National Security Agency, and the Treasury Department's financial crimes unit. source