As the professional networking site LinkedIn investigates the theft of millions of members' passwords, more sites have admitted similar breaches.
The US dating website eHarmony and the British-based music site Lastfm.com said some of their user accounts were compromised a day after the professional networking website LinkedIn admitted a major security breach.
LinkeIn said it is working with the US Federal Bureau of Investigation (FBI) as it investigates the suspected theft of 6.4 million member passwords.
The websites are urging users to change their login details.
Security experts say users may receive fake emails that purport to warn about the breach but which are also attempts to steal personal data, a process known as "phishing."
za/sms (AFP, Reuters)