In that law, it's specifically by using a device, presumably one that enables the user to hear things their unaided ears could not. The law doesn't cover eavesd

In that law, it's specifically by using a device, presumably one that enables the user to hear things their unaided ears could not. The law doesn't cover eavesdropping by being present and undetected using unaided ears. A similar law could be written to cover viewing using magnified optics; existing laws in the US are usually written in terms of a reasonable expectation of privacy, which is not always clearly defined. I think anything viewable from a public place with an unaided eye would probably not fall under that category.