Microsoft Office 365 goes down
Users have been complaining that they've been blocked from accessing Office 365 portal, and checking Down Detector and such, there is indeed a spike in people reporting problems with the service.
Checking the Azure status page, it says: "Starting at approximately 09:00 on 3rd Dec, 2015, customers began experiencing intermittent issues accessing Azure services that use, or have dependencies on Azure Active Directory."
"Engineering teams have identified an Azure Active Directory configuration error that is believed to be the root cause of the issue. The team is working on failing over the impacted service components to a different environment. Impact is largely centralized to the West Europe and North Europe regions. An update will be provided in 60 minutes, or as events warrant."
This seems to be only affecting those who are trying to access the services through their browser, rather than apps or desktop software.