Top U.S. wireless carrier Verizon will temporarily network-lock all of the mobile phones it sells in an effort to deter theft and fraud, according to a Cnet report today. The move comes after years of a more relaxed policy whereby Verizon sold customers unlocked phones, immediately enabling their use on rival domestic and overseas cellular networks. According to Verizon, phones will begin to arrive locked by default, an initial change intended to reduce the theft of new phones that are either en route to or sitting inside stores. Verizon is also making a second change this spring: implementing an unspecified wait period for unlocking in an effort to stop scammers from using stolen identities to sign up for services, get new phones, then immediately sell the phones and disappear. Assuming that the theft and fraud problems are as serious as Verizon suggests, the new policies appear to be reasonably consumer-friendly. Until the second change happens in spring, Verizon will automatically unlock a new phone as soon as a customer signs up and activates service. In spring, once the waiting period is in effect, the unlock will happen either manually or automatically after a yet-to-be-specified period of time. This will likely only inconvenience people who plan to travel internationally and use foreign SIM cards soon after buying the phone. As Cnet notes, all of the other major U.S. carriers have unlock waiting periods ranging from 40 to 60 days after the device has been fully paid off. Unlike its rivals, however, Verizon says that it will unlock the phone after the waiting period regardless of whether its paid off. Verizon has an agreement with the FCC not to limit its handsets ability to work on rival networks, which the company claims — perhaps incorrectly — that its new locking policies will follow, at least in spirit.