Several technology companies have urged the public to reset their passwords amid fears of a major security problem with a product used to protect people's personal data.
The Heartbleed bug affects OpenSSL, which many companies use to protect sensitive information, including people's password.
A small padlock icon appears on websites using OpenSSL to reassure users, but the loophole in the programme could have left it open to exploitation by hackers.
Blogging platform Tumblr posted a public notice about the bug, advising users to "take some time to change your passwords everywhere - especially your high-security services like email, file storage, and banking".
Finnish security company Codenomicon also said it would be "a good idea" to change potentially vulnerable passwords.
More top news
Twitter thinks Bob Hoskins is another of 2016's celebrity victims - but the actor actually died in 2014.
Turkish riot police used pepper spray against protesters who were attempting to defy a ban and march on Taksim Square to celebrate May Day.
The Midland's city is in carnival mood as Leicester City face Manchester United in a match that could secure them the championship crown.