you can obtain a nice SSL certificate for your own webservers; yet for those who likes NGinx like me this guide How To Secure Nginx with Let’s Encrypt on Ubuntu 14.04 | DigitalOcean is also useful

In this tutorial, we will show you how to use Let’s Encrypt to obtain a free SSL certificate and use it with Nginx on Ubuntu 14.04. We will also show you how to automatically renew your SSL certificate. If you’re running a different web server, simply

Since it’s based on US of America your can’t really trust them for “national security” issues or even when there’s business involved or you strive for real privacy. For that level of trustness the only way are self-signed certificates distributed with a one-to-one physical channel.