I was recently burned by this. The client had left his server misconfigured for a few hours, and a lot of his static content ended up in a redirect loop. I was

I was recently burned by this. The client had left his server misconfigured for a few hours, and a lot of his static content ended up in a redirect loop. I was called in to fix the mess. Although modern browsers are clever enough to detect a redirect loop and throw an error, they're not clever enough to detect when the redirect loop is caused by a cached 301 response. So they cache the redirect loop as well. Throw in another layer of caching (CloudFlare), and now you've got a bunch of URLs that will be stuck in a redirect loop for a very long time. The only solution was to append some garbage to every URL, like "?cache=no". Fortunately, the problem only occurred with static content, so nginx happily discarded the querystring and returned fresh content.