As far as I know there is no legal precedence (and I'm not a lawyer), but I think that figuring out data formats and protocols counts as "ideas and principles"

As far as I know there is no legal precedence (and I'm not a lawyer), but I think that figuring out data formats and protocols counts as "ideas and principles" -- which is okay. It's hard to say, really, courts aren't famous for showing any understanding of computer science. There is the DeCSS-case, which led to acquittal in Norwegian courts: http://en.wikipedia.org/wiki/DeCSS http://en.wikipedia.org/wiki/DeCSS