The two people who shut down four Washington power stations in December were arrested . This is the interesting part:

Investigators identified Greenwood and Crahan almost immediately after the attacks took place by using cell phone data that allegedly showed both men in the vicinity of all four substations, according to court documents.

Nowadays, it seems like an obvious thing to do—although the search is probably unconstitutional . But way back in 2012, the Canadian CSEC—that’s their NSA—did some top-secret work on this kind of thing. The document is part of the Snowden archive, and I wrote about it:

The second application suggested is to identify a particular person whom you know visited a particular geographical area on a series of dates/times. The example in the presentation is a kidnapper. He is based in a rural area, so he can’t risk making his ransom calls from that area. Instead, he drives to an urban area to make those calls. He either uses a burner phone or a pay phone, so he can’t be identified that way. But if you assume that he has some sort of smart phone in his pocket that identifies itself over the Internet, you might be able to find him in that dataset. That is, he might be the only ID that appears in that geographical location around the same time as the ransom calls and at no other times.

There’s a whole lot of surveillance you can do if you can follow everyone, everywhere, all the time. I don’t even think turning your cell phone off would help in this instance. How many people in the Washington area turned their phones off during exactly the times of the Washington power station attacks? Probably a small enough number to investigate them all.

They’re using commercial phones, which go through the Ukrainian telecom network :

“You still have a lot of soldiers bringing cellphones to the frontline who want to talk to their families and they are either being intercepted as they go through a Ukrainian telecommunications provider or intercepted over the air,” said Alperovitch. “That doesn’t pose too much difficulty for the Ukrainian security services.”

[…]

“Security has always been a mess, both in the army and among defence officials,” the source said. “For example, in 2013 they tried to get all the staff at the ministry of defence to replace our iPhones with Russian-made Yoto smartphones.

“But everyone just kept using the iPhone as a second mobile because it was much better. We would just keep the iPhone in the car’s glove compartment for when we got back from work. In the end, the ministry gave up and stopped caring. If the top doesn’t take security very seriously, how can you expect any discipline in the regular army?”

This isn’t a new problem and it isn’t a Russian problem. Here’s a more general article on the problem from 2020.