I have created a few posts with featured images on my blog. Since this is self-hosted installation, I was more than sure, that all my files were upload to my server / hosting. But to my extreme surprise, when checking source I have found, that they're served from Wordpress.com (example code: <img src="http://i0.wp.com/BLOGDOMAIN/files/2015/08/FILENAME.png">
) instead of for example http://BLOGDOMAN/files/2015/08/FILENAME.png
.
What am I missing? How can my private, self-hosted blog post anything to Wordpress.com? I've never agreed for something like this. I'm a privacy maniac and the only reason for spending hours on setting own, self-hosted blog network was, that I don't want to have anything related to Wordpress.com.
Can someone enlighten me, what is causing this strange (at least to me) behavior of my self-hosted blog? Is this some magic in theme that I use or a hidden feature of Jetpack? Is there any way to disable this? Can I have my private, self-hosted blog network really private and prevent it from sending or uploading anything to Wordpress.com?