A recent scandal regarding Windows Live Messenger blocking messages that contain links to popular sites including YouTube.com, DeviantArt.com and GooglePages.com has reached the creators of the instant messaging software.

Windows Live Messenger has recently stopped delivering messages containing URLs from a series of popular sites and the sender would receive an error: "The following message could not be delivered to all recipients" The error would not display when the URL is missing the "http://" prefix (e.g. youtube.com) but the message would still remain undelivered.

Within 24 hours Microsoft unbanned the YouTube site and shortly after, project manager for Windows Live Messenger, Dharmesh Mehta released a statement on the Windows Live Messenger blog explaining the cause:

"- There are a number of factors that can be used to determine whether a URL is potentially harmful: number of times a URL is sent, the frequency of the URL being sent, the number of accounts the URL is sent from, manually checking the URL, comparing with other "block lists", etc.
- When a URL is deemed harmful, a block can be instated for a specific URL (i.e. www.domain.com/page) or an entire domain (i.e. *.domain.com)
- This entire process for Messenger is managed by a 3rd party that is a Microsoft partner
- On Friday, Microsoft did not request to block any of the URLs that were accidentally blocked
- The blocks were made by our partner as a result of their process to block harmful URLs
- We are still investigating the specific reason our partner made these incorrect blocks and we will work with them to improve their process for detecting harmful URLs while not blocking safe ones."

The 3rd party company that runs the faulty server-side filtration software for Windows Live Messenger remained undisclosed. At this time, several other sites including GooglePages.com and eBuddy.com still remain blocked.