Dear All,
I have ask also "Groundspeak" for this concern. They answer was as follow:
COPY:
Hello Peter-
Thank you for contacting Geocaching HQ.
It is allowed to make a "copy" or replacement version of a trackable to travel if owners fear that other geocachers might just take the original trackable (because it is very desirable for some reason) or because the original trackable got stolen but they still have the TB code.
As long as the TB number exists in our database, it can be logged.
The basic intend of trackable has been destroyed for me! But it is legal! Therefore I have forwarded also this mentioned copyied TB into the next cache (TB-hotel)!
I will no longer hunt this kind of TB, if they pass my way ok! The basic intension of this HQ-Game is destroyed!
So long from rainy GERMANY!