US Senator Ron Wyden has raised the alarm multiple times about the insecurity of SS7 and US Telcos' unwillingness to invest in SS7 firewalls to stop unwarranted

US Senator Ron Wyden has raised the alarm multiple times about the insecurity of SS7 and US Telcos' unwillingness to invest in SS7 firewalls to stop unwarranted requests from outside their networks: https://www.theguardian.com/world/2020/mar/29/revealed-saudis-suspected-of-phone-spying-campaign-in-us https://www.theguardian.com/world/2020/mar/29/revealed-saudi... https://arstechnica.com/features/2019/04/fully-compromised-comms-how-industry-influence-at-the-fcc-risks-our-digital-security/ https://arstechnica.com/features/2019/04/fully-compromised-c... SS7 is slowly being replaced by DIAMETER (itself the successor to RADIUS, see what they did?) inside carriers' own networks, but most carrier-to-carrier interconnections still run on the legacy SS7 protocols.