Final answer:
The leading form of identity theft in the United States involves the fraudulent use of Social Security numbers. These numbers provide access to financial and credit resources, making them highly valuable for identity thieves.
Step-by-step explanation:
The question posed concerns the most common form of identity theft in the United States, which is the fraudulent use of personal information. The options provided include Social Security numbers, email addresses, passport numbers, and fingerprints.
Social Security numbers are, by far, the leading target for identity theft. This type of personal information is particularly valuable to thieves because it can unlock access to a victim's financial accounts, allow for the opening of new credit lines, and facilitate the committing of other forms of fraud.
Individuals can minimize the risk of identity theft by taking certain precautions, such as using complex passwords, securing sensitive mail, monitoring their credit history regularly, and being cautious when sharing their personal information online or with unfamiliar parties.