Just a EU perspective here. There are EMC directives and norms, they generally work like this: the amount allowed for emission needs to be accepted without dist

Just a EU perspective here. There are EMC directives and norms, they generally work like this: the amount allowed for emission needs to be accepted without disturbance (there are two different categories like industrial and non-industrial). Let me give you an example. non-industrial is not allowed to emmit more than 3V/m, but non industrial product are also not allowed to be disturbed by 3V/m. So far so good. This only applies to 'disturbances' or 'non use signals'. Let me explain: Now, radio transmission is different (like a mobile phone). The use signal (which is not a disturbance) is allowed to be much higher, like 40V/m. (So there was a case where a coffee machine broke when putting the mobile on it). This is all in perfect compliance. (of course the manufacturer of the coffee machine hardened the device, but this was market forces). So for the other direction, I am not too sure but it can perfectly fine that the allowed EMC disturbs the reception of a radio signal device. Also EMC is only tested in 'typical' situations. About the legality by using Software to intentionally transmit signal (def not legal without HAM license or proper FCC testates) I have no idea who would be the liable party i n this case.