NEW YORK (TheStreet) -- If you're thinking of logging on to eBay to buy that Nike putter or L.L. Bean hiking boots, the online auction giant has a message for you: Don't do it until after you change your password.

Don't worry, you'll have plenty of company. According to company figures, the online auction site boasts 128 million registered users and 500 million item listings.

Those numbers tend to attract identity thieves, and eBay reports cyber-thieves crashed the site in February or March. The company uncovered the problem two weeks ago, and executives are advising users to change their passwords to better protect data.

Strictly speaking, eBay users' financial data (including such things as credit card numbers and checking account figures) weren't compromised, but customer names, encrypted passwords, email addresses, phone numbers, home addresses and dates of birth were, and cyber-thieves routinely use that information to unearth consumer financial data and commit identity fraud.

It's a huge threat to consumers; 13.1 million Americans were victimized by identity fraud last year, according to Javelin Strategies.

Here's more information put out Wednesday from eBay headquarters in San Jose, Calif.:

After conducting extensive tests on its networks, the company said it has no evidence of the compromise resulting in unauthorized activity for eBay users, and no evidence of any unauthorized access to financial or credit card information, which is stored separately in encrypted formats ..

Cyber attackers compromised a small number of employee log-in credentials, allowing unauthorized access to eBay's corporate network, the company said. Working with law enforcement and leading security experts, the company is aggressively investigating the matter and applying the best forensics tools and practices to protect customers.

The company said it was reaching out to users via email and other communications channels to advise them to change their passwords immediately.

Per company policy, the new passwords have to have certain combination of characters, and eBay advises choosing a password that's secure but still easy for you to remember. To help you remember your password, consider using a phrase or song title as your password, the company says.