This is a completely incorrect statement. All browsers cache SSL content, as long as you specify the correct Cache-Control headers.
A simple curl request reveals that jquery served from Google’s CDN has Cache-Control public.
Notice the Cache-Control: public header. Moral: be careful putting blind trust in blog articles. And, use Google’s CDN so we can all browse the web faster.
David’s responded by saying that the real problem (and the point of his blog article) is that there are identical versions of each resource in Google’s AJAX CDN, one of which is served through HTTP, and the other is served through HTTPS, i.e:
This causes cache fragmentation because sites may choose either option. However, if you visit Google’s AJAX CDN, they seem to be listing only the HTTPS url. This is a good compromise because it avoids the mixed security issue outlined in David’s post.