Here are five tips to protect your identity online.

1. Change passwords once a month. Passwords are the keys into your life. If a criminal gets access to your email or any of your online accounts, it's surprisingly easy for them to worm their way into other aspects of your life.

Assume your passwords will periodically get compromised. Adobe, AOL, eBay, Kickstarter and Yahoo have all had major security glitches in the past few months.

2. Give the wrong contact information at checkout. Recent data breaches, like last year's Target hack, show that companies aren't responsible enough to safeguard that information. Every time a store clerk asks for your zip code or phone number, that data gets aggregated. So retailers not only have databases that show where you live. They can find out much more about you, like your salary, credit history and birthday.

3. Need photo ID? Don't show your driver's license. This is a general rule for privacy. Don't reveal more than you have to. A driver's license shows your birthday and address.

Next time your doctor's office asks for identification with a photo, show them something else, like your office building badge.

4. No banking apps. Be particularly careful about access to your bank accounts. Although most credit cards have fraud protection, your checking and savings accounts don't.

Because of how easy it is for a computer to get infected with a malware that spies on you, we don't recommend shopping and banking on the same computer.

5. Keep one email account for junk mail only. When companies demand an email address, give them a dummy address. That way you don't have to be bothered with all the spam and annoying advertisements; and it shields your real email from junk. Plus, if those companies get hacked, your real account remains safe.