ADF does actually work otherwise they wouldn't sell it at £5-7 for a 1mx1.4m roll. It reflects heat, or absorbs it, I forget how it works exactly. The fact of the matter is the feds in the sky arn't fucking interested in you and your 400w HPS or whatever. If you have a number of 1000wHPS then you have something to worry about but reality wise it would cost them more in gas to fly over your house than the amount they would get from busting you. Plus, its seriously exagurated just how effective heat sensory is, especially from up above. You should be worried about police on the ground who use the equiptment for that specific purpose. So far only one place comes to mind that I read about, that got busted, the entire house, room to room, was filled with MJ, and the heat was so emmense that they picked it up because the roof was smoking with heat. Come to think of it when you see Police, Camera, Action, or whatever, do you ever see people in their houses? Can you see anything besides civilians on the street? Cos I don't.