Aside from the losses mentioned earlier in coaxial cable, (IR loss, Dielectric Losses, and Radiation) under radiation, aside from the percentage of shielding, the resistivity of the shielding also comes into play:
"For shielding to work perfectly, the shield conductor must have no resistance. If you look up the skin depth formula, one of the terms is sigma, the conductivity of the material. If sigma is small, the skin depth gets big. John" So 100% shielding does not mean 100% containment, necessarily. 73, Steve NU5D
