If they are focused on you then they can probably do that although it may take considerable work, such as spidering an entire web site to correlate resources on the site against timing and size information.

Without encryption we know the NSA takes the approach of just bulk collecting everything they can to filter after the fact.

So rather than an assigned agent trying to discern what Public Enemy #1 Lammy is up to right now, and painstakingly concluding you have probably just read a Wikipedia article about Jaffa cakes, if you don't have encryption what happens is that the automation notes "Lammy looked at http://en.wikipedia.org/wiki/Jaffa_Cakes" as you click and it goes into the vast heap of stuff snooped that second even though you aren't under any suspicion and it's probably irrelevant.

This bulk surveillance is an unjustified attack on everybody's privacy.