They imply it only collects the public data available-- not the private data. It is therefore only useful as a tool to make associations with, and make inferences, using otherwise beniegn data points.
The fact this is publicly available data is key here. An NPR article I heard earlier wasn't clear on that fact. If it's simply data mining what is already out in the public, I can see how it wouldn't be valuable. If it has some sort of high level access that can see conversations marked private, that's a different story.