The heroes had set up security camera's around your base when you weren't there, in hopes that they'd find out more information about you. They didn't know that you knew about the camera's. When they looked at the live footage from your base they saw you talking to a friend as if it was some sort of podcast.

Endeavor: What the hell?..

Aizawa, Allmight, Hawks, Midnight and some other pro heroes were watching the live footage