This is a wonderful interview question: You're running IT in a hospital and after replacing an MRI machine, Apple devices newer than the iPhone 6 all start to fail. Older devices are fine and Androids, PCs, etc. are not affected. Try to guess before you read the answer.
Store your cold bitcoins like the pros. Practice writing Smart Contracts(tm) like the pros. Where is the "hard fork like the pros" link? Oh I guess BCH is forking again, yawn.