The head of MI5 has accused Facebook of giving a “free pass” to terrorists with its plans for end-to-end encryption. Ken McCallum said the plans by chief executive Mark Zuckerberg would enable terrorists to plot attacks without being visible to the security services. In an interview with Times Radio, McCallum said they were not seeking to build a “surveillance state” with “a camera in everyone’s living room.” However, he said there are “rare” occasions when–with appropriate safeguards–it was essential to gain access to the content of messages exchanged by dangerous suspects. McCallum said decisions taken by executives in Silicon Valley were now having a direct effect on the ability of the security services to disrupt the activities of terrorists or child sex abuse rings. “It is the case, especially around default encryption, that decisions taken in California boardrooms are every bit as relevant to our ability to do our jobs …