Directv used the test payloads RB-1A on D11 and RB-2A on D12 to investigate this. They found that depending on where you fell in the line of sight to between the uplink dish and satellite, you could be affected up to a mile away. But they didn't give any figures on what they meant - was "affected" meaning they could measure a db drop in SNR, or meaning that reception was impossible. Suffice to say if you are within a few blocks of an earth station doing Ku uplinks you might have problems. As for Directv's ability to monitor it, maybe with the huge dishes they use it isn't as much of a problem as with the comparatively tiny Slimline.