I think the authorities are already behind the curve, all the criminals/terrorists will already be using VPN's, data encryption and obfuscation!
They will gather a lot of chatter, look for patterns and lets say we exchanged a few emails that had certain words we would be dawn raided!
Think the gov will follow the Americans, limit the use of encryption, extend the RIP Act 2000 and we are all criminals!
What bothers me is some idiot will leak our data and we'll end up having our I'd stolen...