An unintended consequence of wearing face masks is that it benefits terrorists. All of the world's surveillance cameras don't do much good if they can't identify those that mean us harm at airports, or bus and train stations.
Dr. Alex del Carmen at Fort Worth's Tarleton State University says governments are worried known terrorists won't be spotted in time.
"What we see now is that our country, and really the world, is very vulnerable right now."
Dr. del Carmen says it's also a threat to regular passengers, who may be misidentified.
"If the computer read is incorrect that individual is going to go through an agonizing two to three hours being detained and questioned by law enforcement for unnecessary reasons."
Dr. del Carmen says all travelers need to step up their game and now, more than ever, if you see something, say something.
"We need to be vigilant and we need to continue to increase our level of awareness, those of us who travel still, to ensure that our nation is protected and if we see something suspicious we report it accordingly."
The federal government says masks can cause the computer algorithms used to monitor terrorists to fail 20 to 50% of the time.