In the not so distant past I read an article on PSFK about how Professor Patti Valkenburg at the University of Amsterdam published a report on how social media is a positive influence on adolescence who want to find themselves. In the excerpt on PSFK Valkenburg goes on to say that texting, IMs, and social networks allow adolescence to experiment with different identities without the accompanying embarrassment that occasionally follows in the real world.
Now I agree with that to a small extent, but unless she singles out the social networks that are completely anonymous then I don't see how she finds it any less cruel than the real world. A recent viral hit on YouTube shows how Valkenburg's conclusions are at least partly flawed. Kerligirl13 had multiple blog posts and videos promoting herself as the end all be all of cool and as expected: the trolls came running. Packs of anonymous users originating from 4chan.org decided to take it to the next level and tormented her relentlessly to the point of police and child protective services getting involved.
The internet can be accessible and welcoming to all kinds of people, but given the nature of the beast it can be so much worse than "real life". Instead of getting teased by a handful of schoolmates, you'll be ridiculed by possibly thousands of people online.
Here is one of the last videos posted by Kerligirl13 before her channel was deleted along with her Tumblr and Myspace accounts.