How is this, in principle, any different from the DOJ using a subpoena to get customer records from an adult store that was allegedly selling illegal explicit material?
Just because you use the internet to commit the crime doesn't make it not a crime.
I’d say a big difference is that in your example the thing that was supposedly sold was entirely illegal to possess for any reason.
The case being discussed is one where someone might be able to use the product to break the law.
So it’s more like demanding that Home Depot, Walmart, Amazon give the names of every American who’s ever bought a crowbar because the DOJ has heard that some people are breaking into buildings with crowbars.
It has been alleged that the government doesn’t want to prosecute these people who are the ones committing the crimes, they “just want to talk” in order to prosecute the company. Not sure I’d trust that without a signed immunity agreement. If I were forced to speak to these goons, I certainly wouldn’t say a word unless they gave me one of those - regardless of what I was using the gadget for.