This is a great, honest and saddening explanation of what Twitter was and has become:
Oh goodness, what fun twitter was in the early days, a secret bathing-pool in a magical glade in an enchanted forest. It was glorious ‘to turn as swimmers into cleanness leaping.’ We frolicked and water-bombed and sometimes, in the moonlight, skinny-dipped. We chattered and laughed and put the world to rights and shared thoughts sacred, silly and profane. But now the pool is stagnant. It is frothy with scum, clogged with weeds and littered with broken glass, sharp rocks and slimy rubbish. If you don’t watch yourself, with every move you’ll end up being gashed, broken, bruised or contused. Even if you negotiate the sharp rocks you’ll soon feel that too many people have peed in the pool for you to want to swim there any more. The fun is over.
— Too many people have peed in the pool - Official site of Stephen Fry.
And this is just referring to the people using it, not the pending Facebook-esque "I'm going to tell you what you want to look at" changes.