MEXICO (CNN)—As social media become an increasingly common battleground in Mexico's drug war, the viral video fueled debate online.
Twitter was abuzz with word of the possible threat Monday, with some posts under the hashtag #OpCartel saying Anonymous had called off its plans to target the Zetas, and others questioning the legitimacy of the video.
Other Twitter users criticized the group.
"Bits and bytes won't work against bullets," said a post on the Twitter account of Angeliner4life. "Don't be dumb, you are messing with real killers."
The most common mode of operation for Anonymous is launching distributed denial-of-service attacks, in which multiple people use scripts to access a website repeatedly, slowing it badly or shutting it down, if its servers can't handle the traffic.
In the past few years, Anonymous has taken credit for disrupting a number of prominent websites, including those of PayPal, Master Card, Visa and the Church of Scientology.
Last month the group claimed it was targeting the Mexican government, launching attacks on a range of official websites, including those of Mexico's defense and public safety ministries.
Online posts have become some of the loudest voices reporting violence in Mexico. In some parts of the country, threats from cartels have silenced traditional media. Sometimes even local authorities fear speaking out.
Last month attackers left ominous threats mentioning two websites on signs beside mutilated bodies dangling from a bridge in northern Mexico.
The message was clear: Post something we don't like online and you're next. "I am about to get you," one sign said.
It was unclear who the two brutally slain victims were, or whether they had any connection to social media. But analysts said that case showed the prominent role technology has come to play in describing and denouncing violence in Mexico.
CNN's Ashley Fantz, Doug Gross and CNNMexico.com's Tania L. Montalvo contributed to this report.