Tech Tent

The leaders of Google, Apple, Facebook, and Amazon are grilled by US lawmakers over abuse of market power. Is more regulation or a break-up of their firms on the cards? Plus, Garmin is the latest high-profile victim of a cyberattack. And we meet the woman responsible for Google’s undersea cables. Presented by Rory Cellan-Jones, with BBC North America tech reporter James Clayton. Produced by Jat Gill.