|Maps of mobile tweeting in London made with our clima.me tool|
The above map shows the morning commute in London on a Friday about 9 am. You can see that people are tweeting mostly from roads near train stations of major roads. People are tweeting as they work their way to work, some people even tweet on boats on the Thames. Twitter shows the commuter routes people take to work.
About three hours later this map shows the tweeting is now located inside of businesses in the city. Since this was taken in the 2 hours before lunch we can only assume that much of this is people tweeting on their phones at work, thus getting around any social media policies their companies may have. In short social media use blocking at work ended with the iPhone.