The warning from leaders in critical parts of U.S. infrastructure is that they are not prepared for a barrage of cyberattacks and want more support.  

"It's my opinion that cybersecurity threats without question represents most persistent danger of U.S. airports in the global aviation system," said Michael Stephens, executive vice president of Tampa International Airport.

"Consider an attack that infiltrates the industrial control systems of a wastewater system and disables the treatment training on the pumps that move sewage," said John Sullivan, chief engineer at the Boston Water and Sewer Commission. "This could result in the release of large amounts of sewage into rivers and streams, harming the natural ecology of receding waters, creating a public health nuisance, and potentially contaminating sources of drinking water."

One cybersecurity expert tells Newsy that if hackers took out the water sector in a populated area, like New York City, that would be considered an act of war, likely provoking a military response.