Hacktivist group Anonymous claims it has "literally explosive" information about a secretive gathering of powerful men that takes place annually in California, and the group may be on the verge of leaking material from the London Metropolitan Police and agencies affiliated with the UK judicial system.

Anonymous reportedly intends to occupy the entrance to Bohemian Grove in California, today as a protest against Bohemian Grove's secrecy.

According to AlterNet, Anonymous may also be gearing up to leak information from several organizations, including the London Metropolitan Police and agencies affiliated with the UK judicial system.

The protest is part of a series of actions decrying the treatment of WikiLeaks founder Julian Assange. The protest is timed to coincide with Assange's appeal hearing against extradition, which began Tuesday.

The occupation of the entrance of Bohemian Grove, combined with the "literally explosive" leak, could make July 13 the "biggest day in Anonymous's history," according to Prison Planet.

Bohemain Grove is a 2,700 acre campground owned by the private men's club called The Bohemian Club. The Bohemian Club's members include prominent business leaders, artists and former presidents. The annual meeting at Bohemian Grove is said to feature a mix of business deals and politics.

Notable members of The Bohemian Club include former US Presidents Richard M. Nixon, Ronald Reagan, Theodore Roosevelt, George H.W. Bush and George W. Bush.

Though the annual Grove meeting is supposedly just a fun summer get-together, it has been the setting of many important business and political deals. Most notably, the Manhattan Project, the project that led to the creation of the first atomic bomb, was born at the Grove in 1942.