Nope - even though we are regulated to 100mW in the UK for 802.11, given a decent gain on the reciever the range you can get out of these things, even through stone is amazing.

I once performed a test for Blackpool airport where I had an 11Mb DS box in a metal security cage in an aircraft hangar. I could still get a useful signal (albeit at 1Mb) from the far end of the runway about 1 km away.

As I used to field test rf environments, I found some interesting things that 2.4GHz signals are badly affected by, the worst ones being cat food and cardboard packaging.

In the open, 2 km line of sight was easy - even got a 6km signal with a clever receive antenna once - but trees stuff your signal up pretty badly.