These cards are called ghost chips. They are made by someone within the company, scence the company has millions of accounts, it is hard sometimes to track. I highly doubt the sims are canadian, as there are a much fewer customers and such thing is easier to catch. There fore most come from US and are on the roaming, after a while the person or a buisness compaion who sold the card for you turns it off so you have to buy another one, the reason it sometimes turns of faster is that due to bandwith amount the company checks the acount and realizing it is fraud turns it off, wich is the cause of early termination. I was actually looking for one of these bad boys to test out, they usually retail from anywhere 150-200. And by the way it is extreemly illigal, it goes towards fraud so it is a criminal charge, but thank god to interent there are slim chancer of you getting caught, so enjoy untill it lasts, but if you have SWAT team rush you dont be surprised.