Originally Posted by
dchristiva
While that's polite, it doesn't "get around" the frown one might get from the carrier. Hidden city ticketing isn't real popular with airlines. Search the FT archives and you can find anecdotes about airlines' response to frequent violators. They may have a similar reaction to those who buy RT tickets but only use the first half (though I'm pretty sure that's less of a problem).
In theory they could sue the OP for breach of contract, since it's something the OP agreed not to do when he or she booked the ticket. I've never heard of a carrier doing that - it's more common for them to cancel frequent flyer accounts. In any event, I wouldn't call.