What's the best way to deter a thief? Ruin the spoils, of course. Verizon, AT&T, T-Mobile and Sprint have agreed to a broad outline that will culminate in the creation of a central database for stolen cellphones. The goal? To block lifted units from functioning on US shores. Over the next six months, each firm will build out its own stolen device database for integration into a larger, central database, said a Wall Street Journal source, with regional carriers joining the effort over the following