I find it very strange that you're citing (a highly erroneous summary of) a Court ruling restricting the right privacy for jail inmates in specific situations, in order to argue that the Court will extend privacy of persons in public places. Actually, the lack of prisoners' rights to privacy, and the right to record things in public areas, are both well established.
By the way, the word you're looking for is "unconstitutional", not "illegal". Even should the Court restrict the right to record--which they won't, it's a well-established right--jurisdictions may establish that right through law anyway.
By the way, the word you're looking for is "unconstitutional", not "illegal". Even should the Court restrict the right to record--which they won't, it's a well-established right--jurisdictions may establish that right through law anyway.