Originally Posted by
CPRich
The only way I can see you having a problem is if you do this repeatedly and intentionally because a round-trip ticket is cheaper than a 1-way ticket. And even then, it would have to be on a very large scale for anyone to care, if at all.
United's Contract of Carriage doesn't seem to prohibited throwaway ticketing.
Only back-to-back ticketing is prohibited under UA's Rule 100-Tickets.
http://www.united.com/page/article/0,1360,2743,00.html