FLIR won't be able to detect the heat of a house until you get into the 5000 watt and higher range. Its not like they will ever be able to tell the difference between a 400 watt HPS and your big screen TV. And how the hell would you get a warrant for it? People actually do grow tomatoes and herbs indoors, do they ever get busted? no! why? because a Judge is Not going to sign a warrant just because the FLIR can see a lot of heat escaping, it could be any of a million things causing that. the most that would happen is some surveillance until they got enough evidence to get a warrant. FLIR alone is not good enough.
People are so paranoid.