This is actually one of the more interesting things about how data is being collected these days... because we (or rather, our machines) now have the capacity to scavenge and parse so much more data than we could've dreamed of before, people, corporations, governments, etc. have already caught on to the idea that you don't actually need to know your angle before you execute. Gathering tons and tons of data may seem completely worthless or missing the point, but the reality is that "the point" no longer exists. It's all just floating data that, when the time comes, either passes through the filter or throws a flag.

Basically, the government may not care who you're messaging on facebook now, but if someone discovers a correlation to some other problem in the future they'll be damn pleased that they have that data.