The Target (TGT -1.68%) credit card breach continues to get worse. First it was just the data on 40 million cards, then it was expanded to include PIN data, and now Target has revealed that personal information for 70 million customers was compromised. Read on to find out what went wrong and how you can protect yourself.

Source: Wikipedia.

Today, Target revealed that information separate from customers' credit card data has been stolen. The information includes names, mailing addresses, phone numbers, and email addresses for up to 70 million individuals. While nowhere near as bad as the theft of data and PIN numbers on 40 million cards, this is another hit to Target's trustworthiness.

Target has tried multiple incentives to stay in customers' good graces, notably a 10%-off-everything sale the weekend after the breach was discovered, as well as a continued promise that "guests will have zero liability for the cost of any fraudulent charges arising from the breach."

While this still does not rival TJX's 2007 breach, which resulted in 100 million corrupted accounts and cost TJX $250 million, it remains to be seen how much worse the situation will get. The initial breach occurred between Nov. 27 and Dec. 15. Experts believe it will be 30 to 45 days before the majority of bad charges surface, meaning Target will have to wait until February to get a good estimate of how much this will cost the company (assuming that no other card data was stolen).

How to protect yourself
At some point next week Target will release specific instructions on how customers can sign up for a free year of credit monitoring and identity theft protection. What can you do now, though?

1. Sign up for BillGuard to monitor your credit and debit cards.

BillGuard is a free monitoring app for your credit and debit cards. It uses crowdsourced data to create the most advanced fraud-monitoring system, which it sells to credit card companies.

2. Use a credit card instead of a debit card.

As Motley Fool Director of Investment Planning Dan Caplinger explains in this video, the different rules that cover credit cards and debit cards mean the same fraud can lead to a much better resolution for credit card users than users of debit cards.

3. Set a calendar reminder for next week to sign up for free credit monitoring and identity theft protection. Target will release specific information next week on this site.