But it is the recent, explosive growth of Uber and other "sharing economy" companies that have attracted the most concern.
HomeJoy recently announced it would shut down in the face of four lawsuits alleging it should treat the people who clean homes on its behalf as employees rather than as independent contractors not entitled to the same workplace protections.
"If a technologist wants to disrupt an industry that has middle-class jobs and replace them with insecure, not-as-good jobs, there has to be a conversation about that," said Heather McGhee, president of the liberal think tank Demos. "Just because there's an app doesn't mean it's anything different. ... It's a question as old as the economy."