Hackers making progress towards unlocking iPhone
 

Efforts to unlock Apple Inc.'s iPhone continued on Monday, with hackers claiming "very significant progress."

The locked iPhone only works with AT&T Inc.'s EDGE network, and cannot be used with cellular service from other providers. Locked phones are generally used to help operators recoup the cost of subsidizing handsets for their customers, but AT&T is not subsidizing the iPhone, which is priced at either $499 or $599, depending on the model. Instead, the phone is locked because AT&T has a five-year agreement with Apple to be the sole iPhone provider in the U.S.