I don't think there is any other technology that compares with social networks on the rate of bad to good consequences and is still widely adopted. Maybe mass manufactured military-spread drugs like they used in WWII. But it's quite hard to quantify those.

But, of course it created a bunch of good thing. Nothing that spreads that widely has only bad consequences. And yes, I like the good consequences quite a lot too. It's too bad most of the companies keeping those networks are adamant in destroying all the good value and keeping only the bad.