Leo Kelion / BBC:
Users are being told to change their passwords on sites that have tackled the bug
Several tech firms are urging people to change all their passwords after the discovery of a major security flaw.
The Yahoo blogging platform Tumblr has advised the public to "change your passwords everywhere - especially your high-security services like email, file storage and banking".
Security advisers have given similar warnings about the Heartbleed Bug.
It follows news that a product used to safeguard data could be compromised to allow eavesdropping.
