Oh, I left this out. Looking into a house with FLIR or any other infrared system requires a warrant in the U.S. Anything that aides the naked eye (besides binoculars, telescope, etc) requires a warrant. Now some people will tell you that the cops are really out to get us and they will use the infrared without a warrant to find people then try to dig up enough legally obtained evidence to get a warrant and never mention the FLIR but I'm not so sure about that.