The arrest and nine-hour detention of journalist Glenn Greenwald's partner at Heathrow Airport has driven home the potential for abuse of anti-terrorist laws. As reported yesterday, David Miranda was stopped and questioned by police under a rarely used British terrorism statute that allows people entering the country to be stopped without reasonable suspicion. According to government figures, only 3 in every 10,000 people are stopped under the law, and of those, 97 percent are released within an hour. But Miranda was held for the full nine hours allowed under the law, after which police confiscated his phone, laptop, camera, and other electronics. The New York Times reports that among the items seized were encrypted flash drives containing files from Laura Poitras, who has been working with Greenwald and Edward Snowden to distribute leaked documents; his trip was also paid for by The Guardian.

In the wake of Miranda's detention, critics have demanded answers from the British government. Greenwald has kept a running list of responses, including calls for reform within the government. The chairman of the home affairs select committee, Keith Vaz, has asked police for an account of the event, asking whether the law was being applied inappropriately. "It certainly is a surprise to me, as someone who was in parliament when this act was passed, that it can be used in circumstances that don't relate in any way to terrorism."

Greenwald has called the act 'intimidation and bullying' by the UK government

Labour Party shadow home secretary Yvette Cooper also asked for more details about the facts surrounding Miranda's case. "Any suggestion that terror powers are being misused must be investigated and clarified urgently," she said. So far, the UK government has confirmed that Miranda was stopped, but it's declined to issue further comment. Greenwald himself has called the detention an attempt at "intimidation and bullying," with no ties to a possible terrorist investigation. The government of Brazil, where Miranda holds citizenship, said the stop was conducted "without justification." And David Anderson, the UK's independent reviewer of terrorism legislation, has urged Parliament to consider adding more safeguards to the law, though he too has asked for a full briefing on the case.

Since Edward Snowden revealed himself in June, most of the public reaction has focused on him. However, Greenwald hasn't totally escaped notice. Rep. Peter King (R-NY), a longtime critic of whistleblowers, called for him to be prosecuted because he "said he has names of CIA agents and assets around the world and [is] threatening to disclose that." David Gregory, host of Meet the Press, has asked Greenwald why he shouldn't be charged with a crime for publishing the information, and some other commentators have followed suit. Now, though, the apparent attempt to either intimidate Greenwald or keep him from obtaining documents from Poitras has provoked outrage during an ongoing "war on whistleblowers."

Update: The White House has acknowledged that it received a "heads up" from British authorities prior to Miranda's detainment, though the Obama administration insists that it was not involved in the operation. "This was a decision that was made by the British government without the involvement and not at the request of the United States government," White House spokesman Josh Earnest told reporters Monday. "It’s as simple as that."