Programmer may specify if object references move along with the object. Default seems to be to not move. Caller constructs activation record of all argument object references. Record is reconstructed on remote machine in case of remote calls. Moving of objects referenced as arguments may be more efficient that callee doing remote operations on arguments.
Threads pass through objects that are referenced.
Remote object operation -process moves to destination node, ie. This removes burden from nodes that do not need to be involved with comunication, but is complicated in case that objects move. If object B then moves, that part of the processes stack associated with B must move as well, and return from C must go to moved location. Object-oriented structure cleanly defines boundaries of all system entities, making extracting the execution state of a process a simpler task. Local execution must be efficient, remote execution must be correct.