You could contact AT&T security dept and see if they are now part of the CEIR/EIR database program. Member carriers can add IMEI's of stolen phones to the db and it will then be blocked on any of the subscribing carrier networks. Even if AT&T is a member, your milage may vary. I know in Canada Rogers is part of this program, but they generally will not add IMEI's of phones stolen from customers to the list (though they have sometimes). They use it for phones that are stolen from their stores or warehouses so that they become less valuable, but they are hesitant to extend this service to customers. Worth a shot if blocking the IMEI's is your goal.
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