If I use Facebook to stay in touch with my high school friends who are church-going Republicans, I may be getting more ideological diversity than in hanging out with secular progressives on the World Politics sub-reddit.

Reddit names are unconnected to real-world identities and it's commonplace for users to create 'throwaway' accounts to reveal sensitive information.

Re-tweeting is a pretty common practice on Twitter, but on an average day, we see maybe one out of 20 posts is a re-tweet.

[According to Twitter] 24 percent of American Twitter users are African-American. That's about twice as high as African-Americans are represented in the population.

The wider world is a click away, but whether we mean to or not, we're usually filtering it out.

People who know me well have learned to insist that I commit to obligations by opening my laptop and putting them onto the appropriate calendar or list - a verbal agreement and a promise to remember won't work.

The uptake on mobile phones in Africa is phenomenal.