[hinkley]

I looked it up. US Carriers were forced by the US government to start blacklisting them in the final months of 2012. They didn't do it voluntarily.

Australia had been doing it since 2003. IMEIs have been around for 30 years? Everyone having a cellphone is still a relatively recent phenomenon, but according to Pew 80% of American adults had cellphones for several years already before carriers were forced to deal with stolen ones.