After the wide chain of scandals over US global snooping that seriously damaged the trust on the top U.S. Tech companies, Google and Yahoo! came forward and took initiative to provide more secure, encrypted and NSA-proofed service in an effort to gain their reputation again among its users.
Now, Microsoft has also announced several improvements to the encryption used in its online cloud
Source: Microsoft Boosts Encryption for Outlook Webmail and OneDrive