Microsoft has detailed how they are working to minimize security risks in the cloud. When critical infrastructure such as water, power, transportation, etc., see a massive number of attacks, they need to be confident in their IT solutions. Microsoft is using their large cloud presence to secure against all types of threats.
Since Microsoft has a lot of public facing cloud solutions, they see a large number of attacks. These attacks continue to evolve in complexity so Microsoft needs to continually improve their security. Having a large cloud is an advantage to Microsoft because they can use lessons learned from one sector and apply pre-emptive fixes to prevent vulnerabilities. This occurs through their Operational Security Assurance (OSA) program. This program uses data from all over Microsoft to keep customers safe.
Keeping a cloud secure and up to date is critically important to high risk customers. Government systems which control the water, power, traffic, emergency systems, etc., all need to be extremely secure. Moving IT systems to the cloud could spell disaster for a town if their system is compromised. Luckily, Microsoft keeps their cloud security on the cutting edge. Microsoft has cloud solutions in Office, Xbox, Dynamics, Bing, MSN, and more. By gathering data on new attacks across their cloud, Microsoft can protect their entire cloud, including customer data against the newest and most sophisticated of attacks.
Here is a short video by Microsoft about this program.Further reading: Microsoft, Security