Identity theft is a crime that takes place when one person uses another's identity as his or her own identity. It's a type of fraud, and people who commit it can be charged under federal law with sentences that vary depending on the extent of the crime. What's important to realize is that even though the crime could take place, some people might not be aware that they were even involved. For instance, if a gas station's pump doesn't completely reset, another person's credit card may be used for the next patron and so on. This could lead to people being accused of crimes they weren't aware they were committing.
Identity theft can take place when mail or personal identification items are stolen or found. For example, if you lose a Social Security card, that could open you up to a number of serious risks, like the abuse of your credit or the use of your identity to get passports or other documents.
As someone who has been accused of committing identity theft, it's your job and the job of your attorney to prove that you're innocent or didn't know you were committing the crime. You will need to have documents or witnesses to testify on your behalf, and if you can prove that you have never had the information about the other person, then that can be helpful.
Identity theft is not always done of purpose; with technology as it is today, it's easier than ever to log into someone's account on accident or to make an order to the wrong credit card just by logging into a public computer.
Source: FindLaw, "Identity Theft," accessed Oct. 01, 2015