Anonymous to Wall Street: We are taking you down on October 11..

PC Magazine:

The threat to "erase" the NYSE from the Internet was not explained, though in comments on the YouTube video, some speculated that Anonymous was planning a Distributed Denial-of-Service (DDoS) attack on the public-facing NYSE.com website, similar to DDoS attacks the group has used to take down websites in the past. Others felt that would only be a minor setback for the NYSE and guessed that Anonymous was planning a larger attack, perhaps even an attempt to actually disable trading on the exchange.