SAN FRANCISCO -(Dow Jones)- An iPhone owner recently installed software that let the device make calls and surf the Web using T-Mobile's cell phone network, rather than AT&T Inc.'s (T).
When he went to have AT&T address a technical issue with the phone, AT&T technicians noticed his carrier switcheroo, declared the phone's warranty voided and ensured the phone could never again be used on AT&T's network.
http://money.cnn.com/news/newsfeeds/articles/djf500/200709240813DOWJONESDJONLINE000209_FORTUNE5.htm
When he went to have AT&T address a technical issue with the phone, AT&T technicians noticed his carrier switcheroo, declared the phone's warranty voided and ensured the phone could never again be used on AT&T's network.
http://money.cnn.com/news/newsfeeds/articles/djf500/200709240813DOWJONESDJONLINE000209_FORTUNE5.htm