A recent study found half of used cell phones examined still contained personal information, such as: social network logins, phone books, call logs, text messages, etc. Stuff that I'd rather not got out. Most phones have good reset settings if you poke through the menu settings enough, it took a bit of work to find out how to deal with our Motorla Razr's last November when we switched to Verizon.
http://www.eweekeurope.co.uk/news/half-of-used-phones-still-contain-personal-info-24600
http://yro.slashdot.org/story/11/03/24/040255/Half-of-Used-Phones-Still-Contain-Personal-Info
http://www.eweekeurope.co.uk/news/half-of-used-phones-still-contain-personal-info-24600
http://yro.slashdot.org/story/11/03/24/040255/Half-of-Used-Phones-Still-Contain-Personal-Info