Monitors like the P2726DEB have Ethernet, a built in webcam and a built in microphone.

Mine only has the Ethernet port, since it has a built in docking station, but they still could take snapshots of what is on my screen. For now, I am trusting DELL a lot more, though. Part of that is having paid about three grand for my U5226KW. At that price they better don't need to spy on me to make money.