A Breakdown of Twitter's 200 Million Users

Twitter recently filed for a $1 billion IPO, and in doing so revealed that the site had 218.3 million monthly active users in its second quarter.
But who precisely are those users? And what are they doing on the microblogging network?
In this Sunday comic, Nitrozac and Snaggy of The Joy of Tech take a stab at breaking down the millions of people who tweet — and, as it turns out, a lot of users are just spambots and parents spying on their kids.