It depends on the wavelength of the radio waves.

This is visible in microwaves, where the wavelength is about 12cm, but the tiny holes of 1mm are small enough that zero (or super tiny?) radiation/radio/EM in that wavelength can pass through, but light (visible light that you can see) has a much, much smaller wavelength and passes just fine.

So, you could also say that a larger mesh (chain link fence?) of conductive material is also a faraday cage, but only affects things with a really large wavelength.

thus, faraday cages have a variable effect, depending on their configuration.