:tinfoil:

[Agelastus]

Might be useful. Including my own, I can see nine networks from my house at this point in time. Two of them unsecured.

I think there may be a problem he hasn't considered here, though.

Windows.

Windows are going to be your big problem, since they usually have much less attenuation than building material.  You can overcome this by getting windows with a metallic tint or by using a high quality thermal shielding.

There is an advantage to reducing microwave signals in your house; WiFi is a spread spectrum technology and by repressing intefering signals the data rate of your desired network will increase.  The disadvantage is that you'll block the desired signals as well; including your cell phone network.  Also if you paint your interior walls with this it will stop signal from going from room to room.

No downside then, as I do not have a cellphone...

[Savonarola]

This guy's talking about 100 GHz and 200 GHz, so I have a hard time swallowing that the paint will resonate at exactly 2.437 GHz with a ±25 MHz tolerance (channel 6 is 2.437 GHz, channel 1 is 2.412, and channel 11 is 2.462- there's a 5 MHz step between each channel).

He says that it will block signals in the cell phone range too, which would be below the 2.5 GHz band.  I would guess that the paint simply provides a high attenuation throughout the microwave band by havinging a high concentration of metal in it.

[Savonarola]

No downside then, as I do not have a cellphone...

Paint away, then.