Any reputable and clueful transit provider these days is performing automated RPKI validation of the prefixes announced to them. In addition to whatever prefix

Any reputable and clueful transit provider these days is performing automated RPKI validation of the prefixes announced to them. In addition to whatever prefix lists might be manually set up on a bgp session. That's only a small piece of the puzzle in network security generally, but is sure better than how SS7 works right now.