A developer of some Ruby Gems pulled the code as a statement against certain entities (DHS) ultimately using the code. Chef gets owned in the process.
ZDnet has a good rundown of the incident:
https://www.zdnet.com/article/developer-takes-down-ruby-library-after-he-finds-out-ice-was-using-it/ [zdnet.com]
It seems that developers at chef may have used an old copy of the dev's code to get things backup and running agian, which seems like exactly the wrong approach.