Excerpt from this article:
In a photo posted to his Facebook account, [Mark Zuckerberg] celebrated the growing user base of Instagram, which is owned by Facebook. An eagle-eyed Twitter user named Chris Olson noticed that in the image’s background, his laptop camera and microphone jack appeared to be covered with tape.
Other publications, including Gizmodo, used the tweet to raise the question: Was this paranoia, or just good practice?
The taped-over camera and microphone jack are usually a signal that someone is concerned, perhaps only vaguely, about hackers’ gaining access to his or her devices by using remote-access trojans — a process called “ratting.” (Remote access is not limited to ratters: According to a cache of National Security Agency documents leaked by Edward J. Snowden, at least two government-designed programs were devised to take over computer cameras and microphones.)
Security experts supported the taping, for a few good reasons…