Google Earth Freakin Rocks... Love it.
As for Terrorists? This is meaningless to them, they don't have the materials or the ability to put sorta decent imagry to any real use. These images are all low res, 1 meter at best in limited areas. Lokos like most of the trully sensitive "spots" that I am aware of have been (ehem) omited, or very low res, or edited out even...
BUT I did find all my homes over the years, accept the current one cause it didn't exist yet. I am pretty damned pleased with the product. Combine this with Map Point, and I can find allmost anything.