Anonymous members have warned that its hacker spin-off group LulzSec will return to action on April Fools' Day, leading to fears of a fresh hacking rampage.
A video that first appeared on YouTube on 17 March, and is embedded below, promises that the group will return on 1 April with "Operation Lulz Day."
Housing little more than images of LulzSec's mascot with the group's "lulzboat theme song" playing in the background, the video gave no hint what would actually happen on the day itself.
Having gone relatively unnoticed when it was posted, the video has since gathered traction online, but has caused confusion among Anonymous itself, with different accounts questioning its authenticity.
Smaller Twitter accounts associated with Anonymous have taken the video as fact, tweeting messages listing the video's warning as authentic.
"Haaaaa F**k the boys are back in town, Dun dun dun! Lulzsec is back in the hacking biz http://pcwrld.us/GEg792 #anonymous," tweeted Anonymous Sweden.
Contradicting the smaller accounts, though, prominent Anonymous news outlet YourAnonNews was less convinced by the video.
YouTube video announces "Return of LulzSec" -- Truth, joke, publicity stunt, false flag, or wannabes? Your thoughts? | youtu.be/rX6Z9x-W5wI— Anonymous (@YourAnonNews) March 22, 2012
The news follows the arrest of several LulzSec hackers including prominent member Sabu, who was revealed to have been an FBI informant earlier in March.
As well as Sabu, the joint operation saw law enforcement arrest a further five alleged LulzSec members around the globe.
Prior to Sabu, in 2011 law enforcement had mounted a similar campaign by arresting several other accused LulzSec members including the group's alleged "PR man" Jake Davis - aka Topiary.
The arrests of the group's central mouthpieces and subsequent lack of activity by the group led experts to speculate authorities had successfully captured the core members of LulzSec.
The group had originally ended its hacking spree nine months ago, reportedly because its members feared arrest. During its active period the group had mounted successful cyber attacks on several high profile targets including The Sun, Sony and the FBI.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago