or the FBI can access to police records when necessary, and sometimes checks said records when mass media indicts them in a conspiracy to harass pressure cooker enthusiasts. Of course, this explanation is far less exciting, but it is based on two assumptions we can be reasonably certain are true.
Now how does that sit with the theory Ms Catalano just might have been a little prone to exaggeration or jumping to the wrong conclusions about who was visiting her and why?
I got the impression from the blog post that a son may have clicked on links possibly relating to how bombs are made. Perhaps the FBI were monitoring who clicks on those links, and then checked for further search activity etc.
I'm not suggesting any of this is warranted obviously (Terrorism isn't a real threat at all), but it does look like it was more than 'just' search terms.
I'm not convinced we know any of the reasons for the visit yet, but it's fairly disingenuous to consider ANYTHING done on an online property, that you don't own, is not public.