As of this afternoon, it was still not clear which agency knocked on Catalano's door. The Guardian reported that an FBI spokesperson said that Catalano "was visited by Nassau County police department … working in conjunction with Suffolk County police department." (Catalano apparently lives on Long Island, most likely in Nassau County.)

Detective Garcia of the Nassau County Police, however, told The Atlantic Wire by phone that his department was "not involved in any way." Similarly, FBI spokesperson Peter Donald confirmed with The Atlantic Wire that his agency wasn't involved in the visit. He also stated that he could not answer whether or not the agency provided information that led to the visit, as he didn't know.

Local and state authorities work jointly with federal officials on terror investigations similar to the one Catalano describes. Both Suffolk and Nassau County's police departments are members of the FBI's Joint Terrorism Task Force (JTTF), Donald confirmed. Suffolk County is also home to a "fusion center," a regionally located locus for terror investigations associated with the Department of Homeland Security. It wasn't the JTTF that led to the visit at Catalano's house, Donald told us. The task force deputizes local authorities as federal marshals, including some in Suffolk and Nassau, who can then act on its behalf. But, Donald said, "officers, agents, or other representatives of the JTTF did not visit that location.

Ever since details of the NSA's surveillance infrastructure were leaked by Edward Snowden, the agency has been insistent on the boundaries of the information it collects. It is not, by law, allowed to spy on Americans — although there are exceptions of which it takes advantage. Its PRISM program, under which it collects internet content, does not include information from Americans unless those Americans are connected to terror suspects by no more than two other people. It collects metadata on phone calls made by Americans, but reportedly stopped collecting metadata on Americans' internet use in 2011. So how, then, would the government know what Catalano and her husband were searching for?

It's possible that one of the two of them is tangentially linked to a foreign terror suspect, allowing the government to review their internet activity. After all, that "no more than two other people" ends up covering millions of people. Or perhaps the NSA, as part of its routine collection of as much internet traffic as it can, automatically flags things like Google searches for "pressure cooker" and "backpack" and passes on anything it finds to the FBI.

Or maybe it was something else. On Wednesday, The Guardian reported on XKeyscore, a program eerily similar to Facebook search that could clearly allow an analyst to run a search that picked out people who'd done searches for those items from the same location. How those searches got into the government's database is a question worth asking; how the information got back out seems apparent.