Twitter Starts Checking User Links, Deleting Them

Twitter quietly started checking the URLs that its users post, a security measure aimed at weeding out links to known malware sites.

As online security firm F-Secure points out, the microblogging service “is increasingly targeted by worms, spam and account hijacking” and can easily filter links posted through it.

Twitter hasn’t announced this initiative and didn’t respond to a request for comment about it.

Now, when posting a link to a fraudulent site, it deletes the tweet and flashes the message “Oops! Your tweet contained a URL to a known malware site!”

Following links in tweets can be a dodgy proposition, since the original address is often obscured through link-shorteners such as TinyURL and In June, Guy Kawasaki, a popular Twitter user, inadvertently spread a malware-infected link through one of his posts.

Those shorteners still provide a way for scam artists to spread malware through Twitter, since it does not block a malware site whose URL has been shortened. itself, however, uses a spam-filtering system so that someone clicking the link would go to a warning page instead of the malware destination.

Click here to read more on this story from the Wall Stree Journal.