In Dubai, we have booths, as well as phone shops, you give them your phone and they will try various phone cards, as even if the phones unlocked, they dont always accept the card. Once hes found a card that works, its fitted for you and set up. The sims are in security bags so can not be tampered with. Having said this, Vodafone are the easiest, both in Dubai and Jordan. And yes it is for security, You even have to sign at the side of your passport number to say its your mobile number. My number was disconnected for no apparent reason, exept' security issues'