User blog comment:Kirkburn/Technical Update: July 5, 2017/@comment-1757994-20170708191317/@comment-126761-20170710143752

We removed support for some older encryption methods recently (particularly TLS 1.0 and 1.1) - this shouldn't negatively affect anyone using modern browsers.

And, indeed, we are working to move more of the site onto HTTPS, which included switching over images in recent months.