I've always wondered the legality of doing things like this. Have there been cases where someone was taken to court (in the US) for reversing an API from a mobi

I've always wondered the legality of doing things like this. Have there been cases where someone was taken to court (in the US) for reversing an API from a mobile app or website? Assuming no malicious action or intent of course. Could the CFAA be used in this case, even if the intent was just to understand the API for personal use? With so many IoT devices out there relying on 3rd party web services that may or may not be around a year from now, I expect that the right to inspect and understand these APIs will become more and more important. Not to mention wanting the ability to build interactions between devices where the manufacturer may not have interest (IFTTT, etc).