<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by MIKESILV:
Only time I think this may be " acceptable"
may be when your flight on airline A gets cancelled and you are then rebooked on airline B and ends up getting miles on both, whether intentional or not.</font>
I've done this. I got miles from both the airline that actually flew me and the airline that I was originally booked on. But I had no problems doing that because the airline that rerouted me was responsible for the problem. I sent them the receipt for the ticket and a letter asking for the miles and they gave them to me.
Now, the question becomes, if you voluntarily give up your seat and get put on another airline, can you ethically double dip?