Further, retroactive punishment (in the form of harassment, being put on watch lists or no-fly lists, etc.) can still occur even in the absence of any specific ex post facto law.
Finally, with the retroactive extensions granted to copyright holders, the potential for this has already happened -- publishers have released new editions out-of-copyright works, only to find those works later placed back under copyright protection.
http://en.wikipedia.org/wiki/Alien_and_Sedition_Acts
http://en.wikipedia.org/wiki/House_Un-American_Activities_Co...
Further, retroactive punishment (in the form of harassment, being put on watch lists or no-fly lists, etc.) can still occur even in the absence of any specific ex post facto law.
Finally, with the retroactive extensions granted to copyright holders, the potential for this has already happened -- publishers have released new editions out-of-copyright works, only to find those works later placed back under copyright protection.