And if this data includes sufficient identifying info, they should be able to identify me as a US citizen. Even phone number would be enough, since I think that and my US social security number are together in various public data breach datasets.
(Yes, my US phone number should be generating foreign location data. I have two eSIMs simultaneously active, one US and one foreign. For odd reasons I don’t think I have proper roaming working for the US number where I am now, but it does work via Wi-Fi calling which does share the country info with the carrier - and I have had international roaming working at other times.)
Why should my SSN indicate citizenship, some might wonder? SSA certainly knows I was granted my SSN years ago as a newborn citizen, and the Department of State knows I hold a current US passport and have never relinquished my US citizenship.