Muhammad Adnan from UCL's Dept of Geography has chewed up 4 million geo-tagged tweets from London, spat out the commonest user names and plotted them on a map. Different colours indicate probable ethnicity. The data were gathered between August and November 2012.
The map follows on from a similar creation made by James Cheshire (also of UCL), which visualised the commonest surnames as taken from electoral rolls. Much like that map, the Twitter visualisation reaffirms just what a mixed city London is. While English names are common, particularly in south and far-east London, they are by no means in great majority.
As always with such things, caution should be exercised when drawing conclusions. The analysis measures tweets rather than tweeters — it could be that a popular name is simply one or two people tweeting disproportionately often, rather than a cluster of same-named tweeters. In addition, not everyone uses their real name on the social network. Finally, certain ethnicities might be more likely to use Twitter than others.
The map coincides with a new analysis of 2011 census data, which shows that only 45% of Londoners are 'white, British', a drop from 58% in 2001.