Microsoft are today investigating a report by technology website Neowin.net that over 10,000 Hotmail account passwords have been posted online, through the debugging website pastebin.com. According to the technology site, the details posted are real user's account details and not simply made up. The details have since been removed from the site.

Users are advised to change their passwords and as a extra precaution change their security question.

Microsoft said in a statement to the BBC News website that they are currently "investigating the situation and will take appropriate steps as rapidly as possible".

Update:
Microsoft have confirmed on their Windows Live Wire blog that the account passwords being leaked are likely due to the result of a phishing attack as they have "determined that this was not a breach of internal Microsoft data". If you believe you have been a victim of phishing, you should change your password and ensure your computer has up to date antivirus protection. Messenger Stuff recommends the recently released Microsoft Security Essentials software for protection which is compatible with Windows XP, Windows Vista & Windows 7.

What to do if you think your account has been stolen
Change your Hotmail password and security question
News Source: Neowin.net - Thousands of hotmail passwords leaked online
View Microsoft's statement: BBC News - Hotmail accounts 'posted online'