As I mentioned back in June, the ‘content blocker‘ (read: ad blocker) feature of Safari in iOS 9 poses a big threat to free, ad-supported sites like this one. No ad revenue equals no money to pay for such luxuries as servers and writers.
Whitelisting the sites you want to support is the easy option, but John Gruber noticed a reference in the Finer Tech blog to an alternative approach you can use on the fly.
One of the nice perks of Safari in iOS 9 is that, even if you have blockers installed, you can long-press the reload button to reload the site with nothing blocked.