From Inside the Grey House:
Ben put the glass on the table, got up and left.
Joseph knew that every room in the house was wired with cameras and microphones. Vincent liked to make sure guests weren’t plotting against him. Joseph reached into his pants pocket and took out a small remote control he always carried with him. Vincent gave him the device when the surveillance equipment had been installed, in case Joseph wanted to have some privacy with Mierka. The device also came in handy when he and Vincent needed to have private conversations.