“As part of a research project, Serapiglia and students at Saint Vincent College tested 80 phones that they purchased for just $83 from Goodwill’s online auction site. Using software that anyone can buy, they were able to extract data from 47 of the 80 phones. Pictures, text messages, e-mails and documents were just some of the items recovered from phones that had been given away by their owners.”
Simply “resetting” a phone does not completely wipe your data from it. You’d do well to remember that, and follow the advice in this article before giving away or selling your old phone.