This is obviously a rather profound escalation of their attacks on the news-gathering process and journalism. It's bad enough to prosecute and imprison sources. It's worse still to imprison journalists who report the truth. But to start detaining the family members and loved ones of journalists is simply despotic. Even the Mafia had ethical rules against targeting the family members of people they felt threatened by. But the UK puppets and their owners in the US national security state obviously are unconstrained by even those minimal scruples.
If the UK and US governments believe that tactics like this are going to deter or intimidate us in any way from continuing to report aggressively on what these documents reveal, they are beyond deluded. If anything, it will have only the opposite effect: to embolden us even further. Beyond that, every time the US and UK governments show their true character to the world - when they prevent the Bolivian President's plane from flying safely home, when they threaten journalists with prosecution, when they engage in behavior like what they did today - all they do is helpfully underscore why it's so dangerous to allow them to exercise vast, unchecked spying power in the dark.