WASHINGTON—Federal Bureau of Investigation Director James Comey
on Thursday said a number of plots near the July 4 holiday by
suspects inspired by Islamic State were disrupted by a spate of
arrests, adding that law-enforcement officials are continuing to
pursue leads as the militant group uses social media in a bid for
followers.
Mr. Comey said "more than 10" people had been arrested in the
past four weeks and they had links to the Islamic State militant
group, though not all of them were charged with terrorism-related
crimes.
"I do believe that our work disrupted efforts to kill people,
likely in connection with July 4," Mr. Comey told reporters during
a briefing at FBI headquarters.
"The reason I say it that way is the nature of these guys," he
said. "It's actually hard to figure out when they are trying to
kill somebody."
He didn't provide details of the suspected plots, and didn't say
that they had been coordinated or directed by Islamic State
militants overseas.
Mr. Comey detailed how Islamic State militants in Syria and Iraq
try to lure Americans to support their network, saying that often a
sympathetic American will follow an Islamic State militant on
Twitter. If the Islamic State militant follows the American back,
the two then begin exchanging direct messages that are masked to
the public—but not to the FBI, once law enforcement has obtained
court-approved authorization.
However, at some point, he said, the American and the foreign
militant will take their conversation into a more secure, encrypted
social network that could prove impenetrable to FBI
surveillance.
Despite those impediments, he said, the FBI was able to arrest a
number of people who had used this social-media approach and he
said more cases are being investigated.
"This is sort of the 'new normal,' " he said. "The work
continues."
Mr. Comey said FBI officials have searched for patterns in the
types of Americans who have proven willing to offer support to
Islamic State, but said the process had proven to be confounding.
He said supporters have ranged from teenagers to a 63-year-old and
said they come from different economic backgrounds—rich, poor, and
middle class.
"What we're seeing now is living proof that social media works,"
he said. "It's the reason Twitter is worth billions of dollars.
It's an extraordinarily effective way to sell shoes, or vacations,
or terrorism."
Mr. Comey said Twitter officials have cooperated with the FBI in
trying to prohibit Islamic State supporters from using the social
network, but he said the militant group has proved adept at
recovering after one person is blocked and at managing to create
new accounts. A spokesman for Twitter declined to comment.
Law-enforcement and national security officials are debating
whether they should do more to completely block suspected Islamic
State supporters from Twitter, he said, or whether it is actually
useful to allow access to the social-media network because it
allows the FBI to track and trace their communications.
Write to Damian Paletta at damian.paletta@wsj.com
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