(Not speaking officially, obviously. I had nothing to do with Haystack anyway). They're images. So you flip a bit every once in a great while; as long as the b

(Not speaking officially, obviously. I had nothing to do with Haystack anyway). They're images. So you flip a bit every once in a great while; as long as the bit isn't part of image metadata, no human user will notice. The next time they load the image, (at least, assuming it's been long enough for it to get evicted from the CDN) they see the right data.