Dan,
I addressed that issue in the first or one of the first aerials I posted. MapQuest.com says that the aerials provided by GlobeExplorer may be copied freely as long as it's for personal use only, not for business/profit use. I ain't making any money off this. I try to keep at least one of GlobeExplorer's logos on the aerials, though I think I've missed a few in the name of saving disk space.