Most likely the site will probably just say that there is a problem with the credit card information and to confirm that it is correct. Since the number is randomly generated and will not correspond to a valid card, the query will be rejected and payment will not be processed. The moment a CC is charged, the business in question (in this case OF) will send that CC number off to whichever CC company it belongs to (or supposedly belongs to), and will directly query that number for authorization. My assumption now is that this will not work for anything that requires any amount of payment, even one as little as $0.10. I have not received any notices from OF or my ISP about my usage of a fake CC, but my attempt a couple years ago did not use that CC to process any payment. I don't know if OF still does that or if they are requiring a small payment now for everything. I only tried this with free subscriptions to OF that did not require any amount of monetary payment at all and it worked for that.
I haven't followed up on this since initially posting about it a couple years ago so my info is out of date.
