Figure 1 .

Partition of users sampled from Twitter into communities. The partition of users sampled from Twitter into communities, annotated with words selected to be typical of those used significantly commonly by each community (only English-speaking communities shown). The top word given for each community is the most significant one in that community. Users send a high proportion of their messages (0.91) to other users within the same community. Circles represent communities, with the area of the circle proportional to the number of users (>250 shown). The widths of the lines between circles represent the numbers of messages (>5000 shown) between or within community. The colours of the self-loops represent the proportion of messages that are within users from that group. A word has been starred to avoid offence.