Mr. Carbuff has done some longer hikes (a week to 10 days at a time) and some of his friends have hiked the AT. Most people do it in sections because they can't get five or six months off to do the whole thing all at once, but the ones who do tend to go looking for another long hike. It's kind of addictive, I gather.
If any of these hikers saw anything, it would probably be really difficult to track them down...