Many clandestine marijuana growers, rather than using metered kilowatts to power their lights, use pirated electricity by tapping the lines and routing it, unmetered, to their grow rooms, reports Jay Hancock of The Baltimore Sun. Utilities have had great difficulty in detecting indoor marijuana grow operations unless they actually spot the illegal lines, because until now they’ve had little real information about what’s going on on their power grid.

But now, technology has produced smart meters which measure in real time how much energy goes into the network and how much is used at the other end by paying customers. Any difference, apart from normal resistance and line loss, is electricity theft.

“Today we are operating blind,” British Columbia Hydro’s smart-meter expert, Fiona Taylor, told The Vancouver Sun. “This system will allow us to follow the flow of electricity from point to point. We will be able to see at a macro level what is happening.”