Mark Zuckerberg concerned about his webcam spying on him

Instagram had reason to celebrate as it surpassed 500 million users as of yesterday, but its celebratory post has garnered attention for other reasons.

It turns out that Mark Zuckerberg, the founder of Facebook, may be concerned about his webcam being used to spy on him. In a post to announce the milestone, eagle-eyed observers spotted that Zuckerberg's laptop has tape placed strategically over its webcam and microphone.

He isn't the first notable figure to be concerned about the prospect of being spied on. Edward Snowden has publicly revealed the existence of a program called Optic Nerve that uses Yahoo web chats to capture images from accounts, while FBI director James Comey has previously revealed that he too puts tape over his webcam.