Child pornography links found in Bitcoin's blockchain

Some of Bitcoin's most important features — the immutability and the distributed nature of its blockchain — might spell trouble for the cryptocurrency. 

A German team of researchers have found some objectionable content within Bitcoin's blockchain, including links to child pornography and, possibly, at least one such image. Since the totality of Bitcoin's blockchain has to be downloaded in order to mine Bitcoin or run a full Bitcoin node — a program that validates transactions on the network — that means anyone who does so is in possession of potentially illegal content.