https://web.archive.org/web/20200618030047/https://www.balti...
https://www.latimes.com/archives/la-xpm-2009-jan-16-na-wiret...
And we know that they have such servers from the events surrounding Room 641A. Snowden also released documents from that incident, such as the NSA attempt to stop publication.
And in my article, the NSA claims they can not legally search such data without a warrant. It doesn't say they are unable to access the data illegally though
No, that is not what xkeyscore is. Xkeyscore is a database for metadata.
> And we know that they have such servers from the events surrounding Room 641A.
And thanks to Snowden's leaks, we now know that these are for tapping communications between foreigners where both foreigners are outside the US.
> It doesn't say they are unable to access the data illegally though
Within the US, they can only do so by asking the phone company to set up a tap, just like the FBI. Your article does not dispute this.