The good folks at EFF report:
We’ve asked the companies in our Who Has Your Back Program what they are doing to bolster encryption in light of the NSA’s unlawful surveillance of your communications. We’re pleased to see that four companies—Dropbox, Google, SpiderOak and Sonic.net—are implementing five out of five of our best practices for encryption. In addition, we appreciate that Yahoo! just announced several measures it plans to take to increase encryption, including the very critical encryption of data center links, and that Twitter has confirmed that it has encryption of data center links in progress.