What scenario would they use [this] info for? Economic espionage, sabotaging foreign trade talks which aren't judged to be in the interests of the US, gaining

What scenario would they use [this] info for? Economic espionage, sabotaging foreign trade talks which aren't judged to be in the interests of the US, gaining the upper hand in negotiations. The potential utility of this sort of SIGINT is high, if you are willing to engage in amoral behaviour on a massive scale, treating allies as enemies. So the question it raises is, why were they collecting this information? You can be sure they would not collect it for no reason.