Anonymous
The Anonymous hacktivist collective has taken responsibility for taking down a number of websites Thursday. Wikipedia

The secretive hacking collective Anonymous is threatening to expose Mexican drug cartel Zeta. Since their earliest activities beginning in 2003, the group has been targeting everything from Sony to Church of Scientology.

In Veracruz, Mexico, an Anonymous hacktivist was kidnapped by people believed to be a part of the Mexican drug cartel. The video was first posted on October 6th. It does not appear that further steps have been taken yet. In the YouTube video translated by the Guardian, the Anonymous member tells the Zetas they've made a huge mistake in taking one of [them], warning that this November 5th will be a memorable one if they refuse to release him.

Anonymous does not say which of their members was taken, but global intelligence Stratfor reports tells that the person was taken during one of their street protests dubbed Operation Paperstorm in Veracruz. The Guardian also reports that Anonymous has been running in with rival gangs in Veracruz.

The Zetas themselves are one of the most dangerous drug cartels known in Mexico for committing violent crimes like assassinations, kidnapping, blackmailing, and illegal drug trade, among other crimes. Anonymous says they have information on the cartel's secrets, including the identity information of journalists, taxi drivers, and police officers that are behind the Zetas. If the unnamed member is not released, Anonymous swears they will publish photos and addresses of these affiliated individuals. The individuals may face arrest if they are outed.

As to how Anonymous obtained this confidential information remains unclear. The collective makes no mention of using hacking to get this information. Twitters of U.S. Anonymous activity have also made no mention of the drug cartels, as they seem to focusing efforts on Occupy movements right now.

In the video, the Anonymous member speaks with Mexican slang in the accent of a Spaniard. The said November 5th date is also Guy Fawkes Day, the unofficial anniversary of Anonymous referencing the movie V for Vendetta during the 1604 plan to destroy the British Parliament. The masks these covertly suited members wear are also worn by the movie's hero.

Every year on this date, Anonymous has been dedicating the day to plot cyberattacks. This year, they already plan to attack Facebook, Fox News, and, now, the Zetas.