Uhm, is it really paranoia in this case? I mean, of all people, I would expect Zuckerberg to be extremely aware of how easily privacy can be breached. The more well-known you are, especially to people on the Internet, the more of a target you will be. So it stands to reason he knows he's a highly visible person/potential target (after all, if you could hack into the CEO of Facebook's computer, what else might you find? it'd be like a potential treasure trove), and also knows how vulnerable one can be to security threats.
Besides, at my office we have Skype now and people can video call you. I guess he doesn't work from home in his PJs from that computer, but I've been known to cover my work laptop camera on a lazy Friday just in case someone tries to Skype me and finds out I'm lounging in no bra and a tank top. It hasn't happened yet, but if I cover up my camera, I don't have to worry it ever will, either.
Would it be more, or less paranoid of Zuck if he were a hot babe? Asking because I have heard a lot about girls' cameras and laptops actually being hacked specifically for the camera, to grab images of them while they are unaware.
Is it paranoia to draw your blinds when you're at home at night and your interior lights make it really easy for everyone to see inside/what you're doing? Or is it just...using resources that are available to you to help you feel less like you are enabling others' creepy voyeurism?