"From September through December 2014, we estimate that at least 46,000 Twitter accounts were used by ISIS supporters, although not all of them were active at the same time [...] Typical ISIS supporters were located within the organization’s territories in Syria and Iraq, as well as in regions contested by ISIS. Hundreds of ISIS-supporting accounts sent tweets with location metadata embedded. Almost one in five ISIS supporters selected English as their primary language when using Twitter. Three quarters selected Arabic. ISIS-supporting accounts had an average of about 1,000 followers each, considerably higher than an ordinary Twitter user. ISIS-supporting accounts were also considerably more active than non-supporting users. Much of ISIS’s social media success can be attributed to a relatively small group of hyperactive users, numbering between 500 and 2,000 accounts, which tweet in concentrated bursts of high volume. A minimum of 1,000 ISIS-supporting accounts were suspended between September and December 2014, and we saw evidence of potentially thousands more. Accounts that tweeted most often and had the most followers were most likely to be suspended. At the time our data collection launched in September 2014, Twitter began to suspend large numbers of ISIS-supporting accounts [...] Account suspensions do have concrete effects in limiting the reach and scope of ISIS activities on social media. They do not, at the current level of implementation, eliminate those activities, and cannot be expected to do this." (Executive summary)