Question: Where is one of the companies that reported the planned DDOS attack headquartered?

Context paragraphs:
CloudNine Communications: CloudNine Communications was a small Internet service provider (ISP) in Britain.  After a crippling DDoS attack in January 2002, it was forced to sell its business to competitor Zetnet.  CloudNine was one of Britain's original ISPs.  It had been in business for six years.

Hit-and-run DDoS: Hit-and-run DDoS is a type of denial-of-service (DDoS) attack that uses short bursts of high volume attacks in random intervals, spanning a time frame of days or weeks.  The purpose of a hit-and-run DDoS is to prevent a user of a service from using that service by bringing down the host server.  This type of attack is to be distinguished from a persistent DDoS attack which continues until the attacker stops the attack or the host server is able to defend against it.

Email storm: An email storm (also called a Reply Allpocalypse) is a sudden spike of Reply All messages on an email distribution list, usually caused by a controversial or misdirected message.  Such storms start when multiple members of the distribution list reply to the entire list at the same time in response to the instigating message.  Other members soon respond, usually adding vitriol to the discussion, asking to be removed from the list, or pleading for the cessation of messages.  If enough members reply to these unwanted messages this triggers a chain reaction of email messages.  The sheer load of traffic generated by these storms can render the email servers inoperative, similar to a DDoS attack.

Red Hacker Alliance: The Red Hacker Alliance (中国红客联盟) is an informal group of Chinese hackers that at one time had over 80,000 members, making it one of the largest hacking groups in the world.  In December 2004, the group took down their website and became inactive until March 2005, when it regrouped and relaunched its site. " Computer World Australia" and "InformationWeek" both reported that members of the Red Hacker Alliance were involved in a planned DDOS attack against CNN.com on April 19, 2008.  CNN reported that they took preventative measures after news broke of the impending attack.

Cloudbric: Cloudbric is a security as a service and WAF (web application firewall) solution developed by Penta Security Systems Inc. that protects websites from SQL injection, cross-site scripting, identity theft, website defacement, and application layer DDoS attack.  It utilizes a 100% core technology based on the hardware WAPPLES.

Botnet: A botnet is a number of Internet-connected devices, each of which is running one or more bots.  Botnets can be used to perform distributed denial-of-service attack (DDoS attack), steal data, send spam, and allow the attacker access to the device and its connection.  The owner can control the botnet using command and control (C&C) software.  The word "botnet" is a combination of the words "robot" and "network".  The term is usually used with a negative or malicious connotation.

Zombie (computer science): In computer science, a zombie is a computer connected to the Internet that has been compromised by a hacker, computer virus or trojan horse program and can be used to perform malicious tasks of one sort or another under remote direction.  Botnets of zombie computers are often used to spread e-mail spam and launch denial-of-service attacks (DOS attacks).  Most owners of "zombie" computers are unaware that their system is being used in this way.  Because the owner tends to be unaware, these computers are metaphorically compared to fictional zombies.  A coordinated DDoS attack by multiple botnet machines also resembles a "zombie horde attack", as depicted in fictional zombie films.

InformationWeek: InformationWeek is a digital magazine which conducts corresponding face-to-face events, virtual events, and research.  It is headquartered in San Francisco, California and was first published in 1985 by CMP Media, later called CMP Technology.

Trinoo: The trinoo or trin00 is a set of computer programs to conduct a DDoS attack.  It is believed that trinoo networks have been set up on thousands of systems on the Internet that have been compromised by remote buffer overrun exploits.

NTP server misuse and abuse: NTP server misuse and abuse covers a number of practices which cause damage or degradation to a Network Time Protocol (NTP) server, ranging from flooding it with traffic (effectively a DDoS attack) or violating the server's access policy or the NTP rules of engagement.  One incident was branded NTP vandalism in an open letter from Poul-Henning Kamp to the router manufacturer D-Link in 2006.  This term has later been extended by others to retroactively include other incidents.  There is, however, no evidence that any of these problems are deliberate vandalism.  They are more usually caused by shortsighted or poorly chosen default configurations.

Supporting paragraphs: Red Hacker Alliance InformationWeek
Answer: San Francisco, California