In an effort to server-side SPIM filter on its Messenger network for blocking malicious URLs in order to keep its users safe from the spread of malware, Microsoft has banned TinyURL.com, a popular URL-shortening service that gets over 1.5 billion hits each month, is being blocked. Since the site can be potentially used to help send users to malicious websites, Microsoft may have done this intentionally.
Microsoft spokesperson told Ars: “We are very serious in our efforts to block virus, malware and other harmful URLs from being passed on to our customers. We're continually working to improve this process so that we can keep our customers safe without having a negative impact on your Messenger service. We are aware that Windows Live Messenger is currently blocking the URL tinyurl.com. This URL is being blocked unintentionally and we are working to take the appropriate steps to remedy the situation as quickly as possible. We sincerely apologize for any inconvenience and disruption this may be causing our customers.”