I don’t believe it is the conversations themselves, just the meta data (when calls were made, what phone numbers, etc). That said, given the current political climate, what about if you’re known to be in opposition of this administration? This data could be used to find out who you know, how often you talk, etc. and be a tool to construct an enemies list, all under the veil of national security.
Now, does anybody believe that *isn’t* already happening?