According to the popular Twitter tool,, London is now the #1 City based on number of Twitter users:

In the top-10 cities with most twitter users, London is followed by Los Angeles, Chicago, New York, Atlanta, Toronto, San Francisco, Boston, Seattle, and Sydney. Good for those folks in England, Canada, and Australia to have three cities in the top ten.

We are wondering: Because "twitter grader" really mostly measures active users, is it also safe to say that London has the most active users among all the cities of the world?

Link to original post