I'd say the NSAs '3 steps' policy is far more likely. The husband interacts with someone overseas who interacts with someone else who is on a list somewhere. [1] The NSA does the routine profile on everyone within three steps of the-guy-on-the-list, some key words generate hits, salaried agents get another address to visit.
That possibility doesn't get hung up on the problematic notion that anyone's setting up such visits based on google searches alone, nor implies a JTTF agent caughed up real information on how they actually got their lead or why they were actually there.
[1] If you're doing business on the Chinese mainland, it seems pretty likely you'll be within three steps of 'potential terrorists', given the whole cyber cold war and economic espionage thing.