[…] There are still many ways in which information from Trump Tower phone calls could end up in the hands of intelligence agents or law enforcement officials — even without any knowledge on Obama’s part.
First, they may have come upon Trump Tower phone calls if a targeted foreign agent was on the other end of the line — this method comes from the Foreign Intelligence Surveillance Court, or FISA court. Or Trump Tower digital chatter might have shown up while authorities dug through the vast quantities of data hoovered up via more sweeping foreign surveillance programs.
Second, the FBI could also have asked for a so-called “pen register” or “trap and trace device,” which record only the parties involved in a phone call. These requests have a lower bar for approval.
While it’s unknown whether any of these scenarios occurred, it’s “very likely that the people in the Obama administration had access to the communication of senior Trump officials in the run-up to the election, because they have very, very broad authority,” said Cindy Cohn, executive director of the Electronic Frontier Foundation, which has advocated for revising surveillance laws.
And given the ongoing FBI-led investigation into potential ties between Trump’s associates and Russian officials, it’s plausible that law enforcement officials and intelligence agencies had an interest in — or simply came across — the communications in Trump Tower, specialists said. The government is also investigating an alleged Russian plot to use cyberattacks and disinformation to help Trump win.