The google charts link at the top of the thread (http://news.ycombinator.com/item?id=2419367) https://chart.googleapis.com/chart?chs=150x150&cht=qr... is served via HTTPS. Their docs don't officially acknowledge supporting HTTPS but it looks like people have been doing it since 2007 (at least - http://groups.google.com/group/google-chart-api/browse_threa... )

Interesting - looks like chart.googleapis.com works over HTTPS: https://chart.googleapis.com/chart?chs=150x150&cht=qr...

but chart.apis.google.com (which Google formerly used) does not: https://chart.apis.google.com/chart?chs=150x150&cht=qr&#...

Turns out I was looking at some outdated docs. Thanks!