The FBI and DHS are warning members of the United States military to scrub their social media accounts due to a growing threat from ISIS terrorists. 

Catherine Herridge reported on "Happening Now" today on the joint bulletin that went out over the weekend. 

The bulletin said the FBI has information suggesting “individuals overseas are spotting and assessing like-minded individuals who are willing and capable of conducting attacks against current and former U.S.-based members of the United States military."

Officials want current service members and veterans to review their social media posts and remove information that could "attract the attention of ISIS and its supporters."

Herridge was first to report in October that an Air Force father and his teenage son were singled out by ISIS sympathizers on Facebook, with both receiving a swarm of offensive messages. 

At that time, an Army intelligence bulletin warned that Islamic State militants were calling on supporters to scour social media for the addresses of U.S. military family members and “show up [at their homes] and slaughter them." 

House Homeland Security Committee Chairman Rep. Michael McCaul (R-Texas) told Fox News that there are new measures in place to stop ISIS sympathizers from entering the U.S.

Earlier this morning, Martha MacCallum sat down with Fox News national security analyst K.T. McFarland to discuss the threat.

McFarland revealed that she was told recently by the president of Iraq that cell phones and social media played a major role in the Iraqi military surrendering to ISIS fighters over the summer.

"He said, do you want to know why that 30,000-person Iraqi army fled from ISIS in the city of Mosul in June? He said, everybody had a cell phone. All the generals took the cell phone to battle and they got text messages from ISIS, saying 'if you don't lay down your arms and run away right now, we're going to slaughter your families.' They put their cell phones down, they took their uniforms off, dropped their weapons and ran away. The soldiers saw the generals were leaving and [said] we're outta here too. That's how it happened," she explained.

McFarland said many U.S. military members who are deployed overseas are heavily dependent on social media to keep in touch with family and friends. 

"Anybody wants to do harm to our military, they just go online, they look at that. They see he's deployed, his family is home alone, now we have a target," she said, adding it is easy and cheap for ISIS to use social media to glean information about potential targets. 

Service members and veterans are also being advised to make sure their social media profiles are set to "private."

Watch her full analysis below: