And you retrieved the data from the surveillance devices as I asked?

They serve as human surveillance devices, recording everything that happens around them.

They found no sign of surveillance devices in the below-floor space.

They spent some time checking again for surveillance devices, but could find nothing.

The use of surveillance devices is being ramped up, too.

She's developed a new surveillance device that's almost impossible to detect.

The mall is equipped with high technology security and surveillance devices.

He had used numerous types of high-tech surveillance devices in the past.

To Kirk, that meant there had to be surveillance devices in place.

There were no guards or surveillance devices that they could see.