McAfee, the antivirus software company, recently released a list of the most dangerous places to give your Social Security number. Many of the places on the list might surprise you – after the jump:

1. Universities and colleges

2. Banking and financial institutions

3. Hospitals

4. State governments

5. Local government

6. Federal government

7. Medical businesses (These are businesses that concentrate on services and products for the medical field, such as distributors of diabetes or dialysis supplies, medical billing services, pharmaceutical companies, etc.)

8. Non-profit organizations

9. Technology companies

10. Health insurers and medical offices

The places are ranked based on the number of data breaches involving Social Security numbers from January 2009 to October 2010. What’s most disturbing is that you must disclose your Social Security number if you want to receive services from most of those places (either as required by law or the groups’ own policies).

So I asked Adam Levin, chairman and co-founder of Identity Theft 911, what people could do to prevent their Social Security numbers from falling into the wrong hands and keep their identities safe. “It’s obvious there is no slam-dunk 100% way to protect yourself,” he says. “Everywhere you turn, you’re going to run into an organization looking for information from you.”

However, you can take steps to lower your risk, he says. And there are things you can do to detect identity theft and limit the damage.

Don’t be so quick to give out your number. As Levin said, a lot of organizations and companies will ask for your Social Security number. But that doesn’t mean they all have to have it. You will be required to provide your Social Security number in any situation that requires your identity to be verified (such as an application for credit or a license) or about which the IRS must be notified. Otherwise, be sure to ask whether the agency, business or organization has to have it. Unfortunately, even though many groups — such as private insurers — can’t require your Social Security number, they might refuse to do business with you if you don’t provide it. In those cases, ask if you can give just the last four numbers rather than your full Social Security number.

Don’t ever give out your Social Security number or any other personal information to someone you don’t know who initiates contact with you by phone, e-mail or in person. For example, if you receive an e-mail that claims that you must provide personal information to claim a refund from the IRS, it’s a scam. The IRS doesn’t request information from taxpayers by e-mail.

Lock away your Social Security card. Your Social Security card belongs in a fireproof safe in your home, not in your wallet. Why? Because if someone stole your wallet, he’d be able to steal your identity, too. And don’t leave your card or any other personal information sitting out where others can see it. Levin says this is a big problem at universities, where students leave wallets, credit-card statements and other items with personal information that can easily be stolen. Be sure to cross-cut shred any documents with your personal information once you no longer need those documents.

Protect your number from cyber thieves. Even though there’s not much you can do to protect your personal information once you hand it over to another business or organization, you can take steps to protect the data on your computer. Make sure you install antivirus and Internet security software on your computer — and update it frequently. “If you buy the software and don’t update it, it’s like becoming a member of a gym and not going,” Levin says. The McAfee Total Protection software is $59.99 (after a $20 rebate) and the Norton 360 software is $79.99. Levin also says you should frequently change passwords for your online accounts and not use the same passwords for financial accounts and social networks.

Control the damage. Even if you take all these steps, there still is a chance that you will become a victim of identity theft. That’s why it’s imperative to check your accounts daily to catch any transactions you didn’t make. “If you have time to check e-mail and a social networking site, you can find time to check your bank and credit-card accounts,” Levin says. And take advantage of the free credit report you’re entitled to once a year from each of the three credit bureaus — Experian, Equifax and TransUnion. Go to www.annualcreditreport.com to get your reports. Rather than checking them all at once, though, order each one separately to spread out your credit checks throughout the year.

If you notice any problems, act quickly to repair the damage. You can contact the credit bureaus and ask them to put a fraud alert or credit freeze on your accounts. A fraud alert, which is free, requires lenders to make some effort to verify your identity before issuing new credit in your name. A credit (or security) freeze prevents the credit reporting companies from releasing your report without your consent. The credit bureaus charge a fee to initiate a freeze, but you might not have to pay if you’re a resident of a state that waives the fee for identity theft victims.

If your wallet (with your Social Security card or any credit cards inside it) is stolen, report it to the police. With a police report, you can place an extended fraud alert, which lasts seven years, on your credit report, and you’ll have documentation that will help you bolster your case if you become a victim of identity theft.

See the Federal Trade Commission’s identity theft page for information about what you can do if your identity has been stolen.