Living with the surveillance state

With the current apparatus there seems to be a difference between vacuuming up data and analyzing it. Why does the NSA gather so much? I suspect it's because they can and, like any hoarder, they think it will be useful one day. Why monitor companies? Well if the "3-hop" theory is correct, most companies will be no more than 3 hops away from an area of interest. With everything else they are trying to do, is the NSA going to bother sifting & sanitizing commercially valuable data? Probably not routinely. But perhaps it is problematic enough that they could.