What Exactly Is Identity Theft?
Identity theft occurs when someone represents that he/she is you by using your personal information and does so for either fraudulent or other unlawful, improper purposes.
Identity theft can occur when someone uses your personal information to open a “new account,” such as a bank account or credit card account. It also occurs in cyberspace when someone uses your personal information to post online in Facebook, craigslist, chat rooms, and more.
In an "account takeover", the person gains access to an existing, legitimate account using your personal information. Someone who uses your personal information to avoid prosecution commits "criminal" identity theft.