>> people should be concerned. >> you never know who is out there watching or hacking. >> reporter: the fbi and homeland security say isis is spotting and assessing individuals in the u.s. who could carry out attacks against soldiers. a much more serious threat than its standard call to jihad. >> this sounds like it's much more specific. it's organized. isis is choosing the targets. >> reporter: members of the military are being told to scrub their facebook and social media sites of any information or family pictures that could make them targets or provide their information. >> information mining is a real threat. >> reporter: this video highlighted the vulnerabilities. >> a geo tagged post. >> this is an environment this particular enemy has proven adept at using. we don't want to give them any more advantage than they're already trying to gain. >> reporter: this comes in the wake two of separate and deadly attacks in canada by supposed isis followers targeting uniformed soldiers there. there is no indication of a specific threat or target, but