Despite my being a very cautious Internet user, I had one of my email addresses hacked twice recently — once by Emusic.com and once by someone on MySpace.com. I have no idea how they obtained certain of my personal information, but my experiences may help you better protect yourself.

The recent surge in popularity of social networking sites has brought about a whole new world of potential online delights as well as Internet hazards. Signing up with a site such as MySpace is easy and totally free. All they ask for is a valid email address and a password. However, do NOT give them the same password you use for your email account — create a different one for any new service you subscribe to.

Well, I assumed my new MySpace password would keep me safe. However, someone hacked into it and sent out messages under my name advertising get-rich-quick schemes along with other assorted scams. Fortunately, MySpace security people noticed this and advised me to change my password while they deleted the hacker's account.

This happened about the same time several strangers on MySpace had asked to be my "friends." I rejected those with obvious agendas, such as "click here to see my nude pics." But some appeared to be legitimate responses to a blog I had posted on MySpace, so I said OK to their being my "friends." Well, never again. No real harm done, but I learned to be even more cautious than before.

As for Emusic.com, I never heard of it/them until a charge appeared on my credit card for "downloaded songs." The entity falsely claims I had signed up for a "subscription service" using the same email address I had used with MySpace. Coincidence? I don't know, but I got my bank to cancel the charge and give me a new credit card.

In this case, Emusic somehow got hold of my previous credit card number. If they got mine, I assume they could get yours. Check your credit card statements very carefully each month. Better yet, set up an online account with your credit card provider and check it every day. More importantly, don't let your card out of sight when making in-person purchases. Dishonest employees have been caught using hand-held "skimmers" which can read the information on your card's magnetic strip.

Even worse nowadays is the accelerating success of identity theft phishing schemes, in which Internet users are tricked into divulging personal information upon receiving an email saying their bank account (or some other service such eBay, Amazon, or PayPal) has been canceled and won't be reinstated until they "update their records."

Some stats claim more identities are stolen by using scavenged credit card voucher duplicates than by using online scams. Mine was stolen in 1961 when I left my BankAmericard in a gas station for about 15 minutes. You can read about that incident here.

Anti-identity-theft programs have become big business in recent years, but be aware that they can slow down your system as they constantly scan for what may be an incoming scam.