There's a reason why all the sweeps are going on right now. Either they have it all under control and they're mopping up - or they feel they've gathered all the info they need from the folks they've been surveilling and they're not going to get much more - or it's way out of control, they know something is coming, they may know what but they don't know exactly where or when, and figure they better nail everybody they can in hopes of stopping some of it. Hope it's the first option, not the last one.
I'm hoping it is the first as well. It would be prudent to raise the threat level right before a major mopping operation.