Seems like the way README images are cached by GitHub is too aggressive.

For instance its braking the Cocoapods' badges like the one from this (README)[https://github.com/CyberAgent/iOS-NBUKit/blob/master/README.md] by replacing the perfectly functional image URL:

http://cocoapod-badges.herokuapp.com/v/NBUKit/badge.png

(The image above may be also wrongly cached!)

By this
https://github-camo.global.ssl.fastly.net/4d850e7dd43feadf363ed44e160b2296e6b21c92/687474703a2f2f636f636f61706f642d6261646765732e6865726f6b756170702e636f6d2f762f4e42554b69742f62616467652e706e67

Seems like using https instead of http works.
https://cocoapod-badges.herokuapp.com/v/NBUKit/badge.png Now https is also broken.