Probably had his laptop with him and they simply traced the gdid to a specific IP address that they determined belonged to the hotel

Edge seems likely. Its settings include:

>Send optional diagnostic data to improve Microsoft products [Includes how you use the browser, websites you visit, and enhanced error reporting. Determined by your Windows diagnostic data setting]

>Allow Microsoft to save your browsing activity including history, usage, favourites, web content, and other browsing data to personalise and improve Microsoft Edge and Microsoft services like ads, search, shopping, news, and Copilot [Includes your history, usage, favourites, web content and other browsing data]

There's a blurb in the article:

>"Massgrave, the group behind Microsoft Activation Scripts, has noted that Windows setup sends hardware info to Microsoft and receives identifiers back that are later used for Store access and licensing. Blocking GDID assignment breaks both activation and UWP apps."

I think probably it sends the gdid back to Microsoft as part of telemetry/updates/MS account periodic re-auth, which lets them know the current IP address, and then once the government has Microsoft's logs and the various target websites' logs, they can correlate based on IP address. I don't think it's actually sending the gdid to the web sites. Maybe.

This serves to further illustrate that nobody should be using Windows for anything that involves the need for privacy. And doubly, triply, and morefold so, nobody should ever sign a Windows machine into a MS account for any reason.

Edge has a feature where it will periodically pull the bookmarks and browsing history from any other browsers you have installed, so they'll then get sent to Microsoft and associated with your Microsoft account. This was initially enabled by default without the user's consent, although I believe now you may have to opt into it if you do a fresh Windows install. I only realized this was a thing because one time my work PC rebooted to install an update, then Edge came up instead of Firefox, but with all my Firefox tabs. I guess this was part of some effort to try to trick old people who wouldn't notice the difference into switching to Edge. Here's a news article about someone else running into this when it started happening: https://www.theverge.com/24054329/microsoft-edge-automatic-c...

well, mostly the name. And the fact MS gave away GDID - IP mapping to the govt.

The ID is generated even if you only create a local user account. I don't know to what extent that affects tracking/telemetry though.