Maybe, just maybe, these people are not actually campers. If they check in at Ft. Wilderness, they have to sign a form that states no pool hopping, among other no-no's. I think because Ft. Wilderness has the "over flow" lot that is open to people visiting the campground and does not have a security guard gate that you need to go through, people from other resorts park there (maybe resorts that are not even Disney property). Disney has no way of knowing what time you arrived, nor does it have an hourly time limit on how long you can stay. The other resorts near the MK have a way of tracking these. Maybe, people are coming over, using the transportation in Ft. W to get to the Marina and then taking the boat to the resort of their choice.
After all, people are booking sites at the campground with no intentions of camping there, but need resort ID's for emh?
Maybe these are the same "campers" that you witnessed or overheard bragging about hopping. O.K., conspiracy theory is over! 


