<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by mlbUMP:
I think it would be significantly harder for the airlines to discover what you're doing if you use unrelated carriers, but they assured me that it CAN be done, and IS regularly done. </font>
If this is true, this raises SERIOUS antitrust concerns in my mind and would be good fodder for a consumer plaintiff's antitrust firm. Essentially, this is airline A directly penalizing a customer for using airline B.
Moreover, this would be great fodder for an invasion of privacy class action suit. What other charges are on your credit card is no business of anyone but yourself and your credit card issuer.