What could happen when “smart meters” now being installed nationwide — and soon in Maine — to provide detailed data about electricity use meet smarter computer hackers? Some very stupid things.

The meters, according to security experts belatedly hired by their manufacturers and the utilities now installing them, apparently are highly vulnerable to being penetrated by hackers, who can override the meters’ very primitive security and take control of them.

Although there’s no evidence of that happening yet, the security experts say hackers could raise or lower people’s utility bills, shut off their power completely, or penetrate the utilities’ own computers to alter their operations — possibly even interfering with large sections of the power grid.

That makes the people who designed these things the stupid ones.

While early computers contained similar vulnerablities, security systems have become far more sophisticated, and viruses that used to shut down thousands or millions of systems are now rare. But those methods weren’t used by smart-meter designers, the experts say.

With the federal government subsidizing installation, and with 8 million installed and 60 million planned in the next decade — including full conversion by Central Maine Power Co. and Bangor Hydro — it’s a little late to be uncovering this problem.

What customers deserve is to have this system put on hold until this bug is fixed.

The accuracy of people’s electric bills — and the system that provides them power — both should be as secure as possible.