I think there's another, much more insidious way that we lose time on Social Media -- we edit out all the times we reload pages or wait for a response.
Think of it this way -- when you upload photos or post a note to Facebook, you click on the link, wait a few seconds, click on the post button, wait a few seconds, upload, wait a few seconds. Or, there's the fact that Twitter is often really slow. We've all seen the Fail Whale when the server cloud can't keep up with requests, so we generally hit the refresh button and get back into the flow.
All those seconds add up and next thing you know, you've spent hours of your life watching animated icons telling you to wait. And you edit that time out; that is, you don't count that as part of what you're doing, it just slips away.
In one sense this is a perfect Buddhist moment of Nirvana -- your mind is blank, you have attained a state of nothingness. In a sense of living life to the fullest, knowing that the clock is ticking... yeah, I think that's where I see the dark side of social media.
It's not that Social Media is bad, it's that the technology, and the way we use it, is stealing away our lives a few minutes at a time. It's no different than rush hour traffic, or waiting in line at the 12 items or less behind someone with 15 items and three forms of payment.
Except you eventually get home, or through the checkout lane. But with phone apps, computers at work, at home, laptops... it's like taking that traffic jam and long line with you where ever you go...