Anonymous abandons plan to expose Mexican drug cartel collaborators

Hacker group backs away from exposing people it believes are connected to Zetas cartel after alleged threat of killings

A plan by the international hacker movement Anonymous to expose collaborators of Mexico's notorious Zetas drugs cartel has come to an abrupt end. A US activist backed away from publishing the names after an alleged counter-threat of mass retaliatory killings.

"This moves the operation from being a risk to knowing that I would be murdering people," Anonymous participant Barrett Brown told the Guardian on Friday.

Brown's withdrawal from Operation Cartel puts an end to one of the most bizarre and confusing episodes in Mexico's drug wars.

It began with a video which appeared online in early October and promised to reveal the identities of people working with the Zetas unless the cartel released an Anonymous member kidnapped in the Mexican city of Veracruz.

The video prompted furious online debate: while Anonymous has previously targeted business and government websites and databases around the world, it was unclear how it could confront Mexico's amorphous – and deadly – drug trafficking organisations. Conflicting messages appeared on Twitter and other social networking sites, with some activists saying the operation had been cancelled while others pledged to continue.

This culminated in Mexico on Thursday when Spanish-speaking Anonymous participants, who had previously pledged to continue, announced that the Zetas had let the kidnapped member go.

They also said that she carried with her a message from the cartel threatening to kill 10 people for every person named and that they had decided to abandon their plans.

Brown, a prominent Texas-based activist and one of the few willing to be named, initially said Mexican hackers had promised to give him information on Zeta collaborators that they had taken from Mexican government sites and that it would be released in the next few days.

But while he said he was comfortable with running personal risks and "passing a death sentence" on those he identified, the wider retaliation threat had made him "rethink my position".

He added that Anonymous would continue to explore ways of using the internet to help spark some kind of mass response to "the near collapse" in Mexico, as he claims it did in Tunisia and Egypt.