A Faraday Cage is made from mesh not solid material. You would need to make shure it is well grounded and of small dimension mesh. It will protext against low power monitoring.
Is the stuff they make fences out of okay for this? My excuse for putting this up (if I have to make up an excuse) is that I'm going to have lots of PC's in the room and I don't want the FCC complaining...
On the topic of lasers, you might also get a IR viewer and search for a laser transmission FROM your house to another site. This would be a very good method of listening in w/ little chance of discovery. Long range also.
Can camcorders be used to detect this? A friend of mine had this old b&w surveilence camera that could pick up an IR beam off a remote. Are the lasers in the same range or do I need IR gear?
Also watch for microwave traps, similar to the Russian trick at the UN or wherever in the 60's. Any metallic container can be resonated and used to listen to the room noise.
How can I detect this? Will the usual microwave oven leak detectors help? I don't want to confuse high frequency stuff (900Mhz or above) as a reason to be paranoid. :-)