Originally Posted by rickg523

If the seat is unpurchased or unassigned, you're just moving, not poaching.
Similarly, if you have an agreement to change seats with someone, that's swapping, not poaching.
Moving and swapping are not really disagreeable. On the other hand, poaching - which means occupying someone else's assigned seat without asking - ought to be dealt with by nothing less than a strong verbal dope slap and unrelenting insistence that the poacher get the heck out of your seat.