These cell phone interceptors have been known for a while. Akin to so called black box servers setup at major data centers to essentially record traffic flow. Both of which have been allegedly used for intelligence gathering.
Not sure if you can do much about it other than separately encrypt both voice and data traffic, assuming that the encryption itself hasn't been breached.
Or the use of hacked firmware or hardware embedded eavesdropping which can be incorporated in most any type of computer device or accessory, which has already been acknowledged to some extent or independently discovered.
You should just assume that any type of communication is no longer private. If it actually ever was?