There have been some changes to the restrictions of llReturnObjectsByID: ( http://wiki.secondlife.com/wiki/Release_Notes/Second_Life_RC_BlueSteel/13 )
integer llReturnObjectsByID(list objects) Requires new runtime permission PERMISSION_RETURN_OBJECTS objects is a list of objects IDs to return to owner Parcel owner, estate owner, and estate managers can not have their objects returned by this method. If the script is owned by an estate owner or manager, this function works for objects located on any parcel in the region. Otherwise, the script can return objects located over land owned by the owner of the script. Throttled at max parcel land impact capacity region-wide per hour. Returns the number of objects that were returned to their owners or an error code.
See also: http://wiki.secondlife.com/wiki/Simulator_User_Group/Transcripts/2013.06.18 (Message from Kelly Linden: "[12:08] Kelly Linden: The updates in the maintenance channel this week include re-enabling the new llReturnObjectsByID function but with some more restrictions (can't return objects owned by the parcel owner or estate managers, similar to llReturnObjectsByOwner)"). --MartinRJ Fayray 20:25, 22 June 2013 (PDT)