I was asking the same question, quoting that exact excerpt in a different thread... and getting pretty hairbrained responses.

After a little bit of digging, I can see ngrok has a sign in option where you can sign in with a GITHUB account.

I suspect that's how Microsoft has a record of someone interacting with that specific website.

Still am unclear how the browser has access to this id, which sounds like it's a registry setting. If browsers are able and willing to just fork over arbitrary registry values when asked, that's a major issue.

And if it's not arbitrary... just THAT value, it seems to suggest complicity on the browsers themselves.

Can I see this id egressing my system if I'm snooping with wireshark? I really really want to understand how and when this value is going over the wire.