Twitter blocks website hack

Twitter says it has fixed a hacking problem.

The short-messaging service announced the fix this morning after mysterious "tweets" of blocked-out text propagated themselves and caused popup windows to open.

Twitter now says the attack has been "fully patched" and no longer works.

The hack had been extra-nefarious, because the tweets activated without being clicked on it was enough for web surfers to move their mouse cursors over them.

The hack only affected visitors to Twitter.com, however.

Various third-party programs used to send and read tweets were unaffected.