There’s a groundswell of domestic support for the Islamic State coming from social media accounts registered in America — chiefly Twitter — which have played a part in the terrorist organization’s “unprecedented” recruitment of U.S. citizens and permanent residents.

That’s according to ISIS: From Retweets to Raqqa, a report released today by the Program on Extremism by George Washington University. It notes that American authorities have acknowledged “250 Americans who have traveled or attempted to travel to Syria/Iraq to join the Islamic State in Iraq and Syria (ISIS),” in addition to “900 active investigations against ISIS sympathizers in all 50 states.”

While “their motivations are equally diverse and defy easy analysis,” the study found that “American ISIS sympathizers are particularly active on Twitter, where they spasmodically create accounts that often get suspended in a never-ending cat-and-mouse game.”

It further notes the existence of “300 American and/or U.S.-based ISIS sympathizers active on social media, spreading propaganda, and interacting with like-minded individuals.”

There’s a presence on other popular blogging sites too, such as Tumblr, where an American was recently arrested by the FBI for re-blogging a pro-ISIS meme.

Aside from their online exploits, American recruits of the Islamic State don’t fit a uniform profile: The report notes that while most U.S.-born ISIS fighters are male and have an average age of 26, they still “differ widely in race, age, social class, education, and family background.”

The state-by-state breakdown of American Islamic State recruits. 

The wave of ISIS-associated activity has also lead to the highest number of arrests linked to terrorism in the post 9/11 era. “Seventy-one individuals have been charged with ISIS-related activities since March 2014,” the report states, while “fifty-six have been arrested in 2015 alone.” Only 40 percent of those arrested have been Muslim converts.

The report states that “a small number of Americans have been killed in ISIS-related activities: three inside the U.S., at least a dozen abroad.”

Meanwhile, Western leaders such as President Barack Obama, France Prime Minister François Hollande and UK Prime Minister David Cameron are primed to step up bombing campaigns in ISIS-held Syrian territory.

The escalated military endeavors come after Islamic State militants killed 130 people in Paris on November 13.ƒ

Photos via George Washington University Program on Extremism, Getty