The Guardian should sue the UK Home Office for the detention of David Miranda. Miranda's arrest seemed to happen because the authorities wanted to intimidate him and other journalists. They did not have a valid reason to detain Miranda. Just because Miranda had information from Edward Snowden does not make him a terrorist.
The Guardian should sue over this obvious attempt to intimidate a whistleblower and thus, source for the Guardian. All this talk of a possible terror suspect is obviously quite bogus. It was a cheap and low attempt to intimidate Glenn Greenwald and thus try to stop further embarrassment of the world's major governments.