Cybervillains have accessed Ebay's password database, meaning that anyone with an Ebay account should change their password as soon as possible.
The company is set to email Ebayers later today - two weeks ago, it discovered that some employee log-ins had been "compromised" by hackers in February/March.
Extensive investigation showed that this gave the attackers access to the corporate network which contains a database full of encrypted passwords.
Your money is safe
The good news is that no financial details will have been accessible by hackers, and the company also says that it sees no evidence that anyone has accessed credit card details as they are stored in a separate encrypted database.
The company also said that all Paypal data is safe as it is stored separately on a secure network, and all Paypal financial information is encrypted.
As ever, you should change your password on any site you've been using the same password on - it's always more secure to use different passwords on different sites and networks.