Calls to break up big tech companies like Facebook and Amazon are getting louder.

After Sen. Elizabeth Warren called for Facebook, Google and Amazon to be designated as "platform utilities" and broken apart from their own services that compete on those platforms in March, other Democratic candidates for president have ratcheted up their own rhetoric on the issue.

Facebook co-founder Chris Hughes himself has called the social network a monopoly that should be forced to shed Instagram and Whatsapp, two major recent acquisitions.

Harvard Business School historian Nancy Koehn joined the conversation on Boston Public Radio Wednesday, delving into the history of antitrust law in America, and ultimately agreeing with those calling for breaking up big tech.

"Antitrust suits that began against AT&T and continued reverberating beginning in the late 1950s and continued reverberating into the 1960s ... arguably created the space and the opportunity for competition," said Koehn. "That very space helped launch a lot of the early, or helped create the early railroad tracks, for digital revolution."

Koehn is an historian at the Harvard Business School where she holds the James E. Robison chair of Business Administration. Her latest book is Forged in Crisis: The Power of Courageous Leadership in Turbulent Times.