Mark Zuckerberg Puts Tape Over His Webcam Is the Facebook CEO acting paranoid, or is this a good practice?

 -- Mark Zuckerberg posted a photo celebrating Instagram's 500 million user milestone, but what's in the background is also getting some attention.

"It is not paranoia. This is basic security awareness and security appreciation," said online security expert Robert Siciliano. "Unfortunately there are many remote access Trojan viruses that can activate and enable a users webcam without their knowledge. That same webcam can also pick up room ambient sounds."

Siciliano told ABC News he recommends everyone — even a billionaire CEO — mask their webcam and also go to their "recording devices" settings to mute their webcam audio.

Mark Zuckerberg’s MacBook security advice? Put tape over the webcam and microphone — David Iannuzzi (@Rom_Duck) June 22, 2016

Security 101, cover laptop webcam and microphone with tape #Zuckerberg — Harsh Bilodiya (@harsh_bilodiya) June 22, 2016

Security 101, cover laptop webcam and microphone with tape #Zuckerberg