[ssssss777]

This isn't spying and the US would not be the only country involved.

Carriers track their own subscribers' locations no matter which network they are on. Inter-carrier roaming agreements require this ability. So it appears the Saudis has a new use for it.

The increased focus on SS7 security actually increases reliance on inter-carrier PSI. PSI is sent to the last known serving MSC to retrieve the number of minutes since last network contact. This info is used to enable a velocity check against a network attached request coming from a new country. It's this type of check that combats SMS interception.

[dontbenebby]

>This isn't spying

Huh? Care to explain this odd take?

Obtaining information about someone's location w/o their permission, by agents of a foreign power, seems pretty textbook spying.

[neonate]

I assume MSC is this: https://en.wikipedia.org/wiki/Mobile_switching_centre_server.

What is PSI? Edit: thanks!

[lmz]

From the article: "Provide Subscriber Information SS7 message"