here in norway afaik its like this:
if you own the software you are entitled to use it

ie if u buy a used game etc, and its orginal ...then u can use it ...
pretty logical imho....
one certain thing is , if you have a special personal regged file , ie froggerng ...u cant sell this to someone else etc.. even if u sell your amiga with everything...
another thing with a serial code imho anyway...
hard debate this really...