These are taking advantage of poor overall security in the cell phone network infrastructure; if phones cryptographically authenticated their base stations, it

These are taking advantage of poor overall security in the cell phone network infrastructure; if phones cryptographically authenticated their base stations, it would be difficult or impossible. It's not entirely clear why more effort hasn't been put into securing this, but a likely hypothesis is that certain law enforcement agencies want it to be insecure, so that they can use it for domestic investigations. Now that the US finds itself on unfriendly terms with foreign spy agencies, this has become a serious problem.