The growing deployment of internetconnected devices into “the infrastructure” may prove to be volatile.

While there is no set definition of the infrastructure, it can be described as society’s basic physical and organizational structures, including utilities, transportation systems, dams, sewage treatment plants and even traffic control.

Devices connected through the “internet of things” are increasingly being used to help operate these complex entities.

The technology will tell a utility’s engineers, for instance, that its water level is too high or too low, or that a smelting processes’s temperature is over its limit and its furnace must be shut off, said Scott Corzine, New York-based senior managing director at Ankura Consulting Group L.L.C., a cyber security consulting firm.

Every internet of things device, whether it is a webcam, a thermometer or another connection, adds an additional entry point into a network, said Gerry Kane, Schaumburg, Illinois-based cyber risk engineer for Zurich North America. “They’re all just like a computer on a regular network,” he said.

Smart devices that can be hooked up to industry control systems “can be potentially harmful if somebody can get access to those devices and then control access” to the systems, said Adam Cottini, managing director of insurance and risk management in North America at Arthur J. Gallagher & Co. in New York.

“The biggest challenges with IoT devices is they’re so easy to deploy, and they’re just exploding in their ability to transfer data from the devices that historically have not been smart,” said Wade Chmielinski, Norwood-Massachusetts based assistant vice president of cyber security at FM Global.

Historically, however, the devices were not developed with security in mind.

“They can wreak havoc at a level potentially more damaging to society than just the inconvenience of stealing your credit cards,” said Mr. Corzine. “If you can hack one of these machines, you can black out” a city or country, he said.

Mr. Corzine said he believes the most serious danger is from nation-states and potentially well-funded terrorist groups that have the wherewithal to launch such attacks and are uninterested, in this context, in financial gains.

These are well-funded nation-states and terrorist groups “that have enough funding to bring smart guys onto the scene,” and have the same impact warfare once did without “dropping a bomb or shooting a bullet.”