There are at least 46,000 Twitter accounts being used by supporters of Islamic state, according to a new study.
Although typical IS supporters were located within the organisation's territories in Syria and Iraq, they were also in the regions being targeted by the militant jihadist terror group.
Nearly a fifth of IS supporters in Twitter used English as their main language when tweeting, and three-quarters used Arabic.
IS-supporting accounts had an average of about 1,000 followers each, higher than an ordinary Twitter user. These accounts were also a lot more active than general Twitter users.
Twitter suspended more than 1,000 IS-supporting accounts between September and December last year, when the study was carried out. Researchers JM Berger and Jonathon Morgan found that accounts that tweeted most often and had the most followers were most likely to be suspended.
They also discovered that much of the terror group's social media success is down to a small group of "hyperactive" users, between 500 and 2,000 accounts. These people tend to tweet "in concentrated bursts of high volume" they reported.
"The ISIS Twitter census: Defining and describing the population of ISIS supporters on Twitter" is published by the Brookings Institution, the centrist US think tank.
The researchers used "sophisticated and innovative methodology" to map the locations, preferred languages and the number and type of followers of the accounts, most of which were tagged with their location.
The authors called on social media companies and the US government to work together to devise appropriate responses to extremism on social media. The problem of extremist use of social media is most likely to be successfully countered "when they are mainstreamed into wider dialogues among the broad range of community, private, and public stakeholders," the researchers found.
The ability of extremists to harness the power of social media is of increasing concern at the highest levels of international government.
This week the new US Pentagon chief, Ashton Carter, said: "This is a social media-fuelled terrorism group in a way we haven't seen yet.
"People who are very distant from any battlefield, from any experience of radicalism, are suddenly becoming enticed through social media."
