I think that social networking websites induce cowardice.
Instead of going out into the world and actually making friends, or putting on your boxing gloves and confronting our enemies in the flesh, we hide behind the comfort of our computer screens, made up names, Photoshop-ed pictures and stupid smiley faces.
For example, I am currently checking how many likes my Facebook status has landed so far, instead of rushing over to the next-door neighbor's house to inform them that, yes, in fact, their little brat's screaming is disturbing my peaceful life, and would they do something about it, or should I be doing the parenting for them.