What’s in a name? Possibly thousands of dollars. That’s the word from law enforcement agents who say that Americans lose millions to identity theft each year.

The term “identity theft” refers to a crime in which a person steals your Social Security number or other private information. The criminal then uses that information to charge items or services on your credit or simply steal money from your bank account. The thieves often operate online, making it especially important to take precautions when surfing the Web.

A new book called “Geeks On Call Security and Privacy: 5-Minute Fixes” (Wiley, $14.95) could help you protect your identity. It offers expert advice on securing your computer as well as simple, step-by-step explanations of topics ranging from stopping viruses and spyware to backing up your data. The book explains these tips and others in detail:

Encrypt Your Computer Data

If your computer contains financial statements, credit card numbers, business documents, names and addresses of friends and family or other private information, consider using encryption software.

Social Security Numbers

Never use your Social Security number as a login on a Web site and do not give your Social Security number if an unsolicited e-mail requests it.

Avoid Automatic Logins

Some Web sites offer to save your user name and password so you can avoid the hassle of logging in over and over again. However, saving this information can make it easier for a thief to steal your identity.

Always Log Out

Before exiting an Internet account (online banking, bill pay, etc.), be sure to click the “Log Off” or “Log Out” button. This closes your session on the site and prevents someone from breaking into your account by clicking the back button on your Web browser.

Avoid Credit Card “Auto Save”

Most e-commerce Web sites allow you to store credit card numbers on their databases to make future transactions faster. Unfortunately, these databases are often targeted by hackers.