The hacktivist collective Anonymous launched a cyberattack against an official U.K. government website late Sunday, in response to the almost nine-hour detention of David Miranda, the partner of Guardian journalist Glenn Greenwald, at London’s Heathrow airport this weekend. Greenwald, who pens the “On Security and Liberty” column for the Guardian and famously broke the Edward Snowden story, publicized the incident in his column, calling it “a failed attempt at intimidation.”

Hours after the detention, Anonymous hijacked the website of the Mole Valley District Council, posting a statement that sarcastically defended the search and releasing the contact information of immediate relatives of U.S. government and military employees who, they snarkily reasoned, might be terrorists.

“You know.... the more we think of it, the more that makes sense,” Anonymous wrote on the website. “Actually, we agree wholeheartedly, and to demonstrate this, we have employed our own Antisec Radical Surveillance Enterprise to uncover some other possible -- indeed, highly likely -- terrorists on account of their relations to employees at the highest reaches of government and military employment in the USA.”

The statement continued, “We have taken the liberty to present this vital anti-terror surveillance information to the authorities in the form of the table below. We encourage anyone who is interested in preventing terror attacks to fully investigate these spouses and siblings and mothers and fathers and son and daughters, before they too are embroidered [sic] in terrible terror plots of the most heinous variety.”

The nebulous organization tweeted out links to stories about the hack under the hashtag #OpLastResort.

According to Greenwald’s account, Miranda was detained by Heathrow security officials while awaiting a connecting flight from Berlin to Rio de Janeiro, where the couple shares a home. The airport official who contacted Greenwald told him that Miranda had been detained under Schedule 7 of the U.K.’s Terrorism Act of 2000, a legal provision that the Guardian has previously called the nation’s “most draconian stop-and-search power.”

“Schedule 7 empowers police officers to stop and question travelers at UK ports and airports without needing reasonable suspicion to believe that the person is engaged in any acts of terrorism,” Zin Derfoufi, a research fellow studying police and crime commissioners at the University of Warwick, wrote in a column for the publication in 2011. “Officers may physically detain the person for up to nine hours; search them and their belongings; strip and search them; take their DNA and fingerprints; question them on their social, political and religious views, and, although the detainee is not under arrest, they are obliged to co-operate even before their lawyer arrives or risk being arrested for "obstruction.'”

That report roughly matches Greenwald’s description of what took place on Sunday, when he was alerted to Miranda’s detention but told that neither he nor an attorney could speak to him. The search reportedly continued for approximately eight hours and 55 minutes, despite the involvement of Brazilian officials and attorneys who were dispatched to Heathrow by the Guardian.

Greenwald further claimed that Miranda had most recently been traveling in Berlin with Laura Poitras, the documentary filmmaker who collaborated with Greenwald on the Snowden story and who is working with him on additional NSA reporting. Greenwald added that security officials questioned Miranda about electronic devices he was traveling with, and confiscated his laptop, cellphone, USB sticks, and other electronic items.

“They completely abused their own terrorism law for reasons having nothing whatsoever to do with terrorism: a potent reminder of how often governments lie when they claim that they need powers to stop ‘the terrorists’ and how dangerous it is to vest unchecked power with political officials in its name,” Greenwald wrote.

In addition to Anonymous' action, the incident sparked outrage from other free-press advocates around the globe, including Amnesty International, which released a statement censuring the UK government for its detention of Miranda on Sunday, calling it “vindictive” and “inexcusable.”

"It is utterly improbable that David Michael Miranda, a Brazilian national transiting through London, was detained at random, given the role his husband has played in revealing the truth about the unlawful nature of NSA surveillance," Widney Brown, the organization’s senior director of international law and policy, told the publication. "David's detention was unlawful and inexcusable. He was detained under a law that violates any principle of fairness, and his detention shows how the law can be abused for petty, vindictive reasons.”