FBI warns US military to scrub social media to prevent ISIS attacks

The FBI has strongly urged those who serve in uniform to scrub their social media accounts to prevent possible attacks by the ISIS terrorist group.

Military members are now looking at their online social media presence for any information that might attract attention of violent extremists, and they've been told to use caution when posting anything online.

"It's sort of like be on the lookout for, or change your behavior because we believe it could potentially put you in harm's way," said former FBI Agent and ABC News Consultant Brad Garrett.

Overnight, the FBI and the Department of Homeland Security released a joint intelligence bulletin saying that ISIS is looking for sympathizers in the U.S. who are "willing and capable of conducting attacks on current and former members of the U.S. military."

Officials are strongly urging U.S. military members who serve in uniform to get rid of anything on their social media accounts that might bring unwanted attention from violent extremists or help extremists learn their identities.

"The FBI and DHS recommend that current and former members of the military review their online social media accounts for any information that might serve to attract the attention of ISIL (ISIS) and its supporters," the federal bulletin sent to law enforcement agencies said, advising that troops "routinely exercise operational security in their interactions online."

Some members of the U.S. Special Forces tell ABC News they have deactivated their Facebook and other social media accounts.

"We can put ourselves in a situation where we are giving the enemy information on where we are, maybe what we are doing," said Lt. Col. Lyle Shidla, Unit Commander.

Copycats who try to launch attacks like the ones in Ottawa in October are a big concern for U.S. officials. In two separate incidents, two uniformed Canadian soldiers were killed by young men who were apparently ISIS sympathizers.

"We understand you're young, you communicate through social media but we're telling you that's how ISIS finds people that they potentially target," Garrett said.

This warning comes as an ISIS affiliate in Egypt announced it has killed an American oil worker, William Henderson. His company says he was killed in August in a carjacking.

U.S. law enforcement posted the warning in advance of the holiday season when many members of the U.S. military travel in uniform.

ABC News contributed to this report.