Those skilled at the housekeeping functions built into SS7 can locate callers anywhere in the world, listen to calls as they happen or record hundreds of encrypted calls and texts at a time for later decryption (Google translation of German original). There is also potential to defraud users and cellular carriers by using SS7 functions, the researchers say. This is another result of security being considered only after the fact, as opposed to being part of the initial design.
The tactic was first proposed as part of the Stop Online Piracy Act (SOPA) in 2011, but three years after the law failed in Congress, the MPAA has been looking for legal justification for the practice in existing law and working with ISPs like Comcast to examine how a system might work technically. If a takedown notice could blacklist a site from every available DNS provider, the URL would be effectively erased from the internet. No one's ever tried to issue a takedown notice like that, but this latest memo suggests the MPAA is looking into it as a potentially powerful new tool in the fight against piracy.