Infowar.Com Forums

Winn Schwartau's (author of "Information Warfare") forums for discussing information warfare, network security and legal hacking. Additional forums include hacking and programming tutorials and challenges.
http://www.infowar.com/

SecurityForumX

Security forums devoted to discussing news items found in the related SecurityNewsPortal website. Discussion topics include viruses, firewalls and system exploits and weaknesses.
http://www.infosyssec.com/forum/

Security Forums Dot Com

Offers support forums on a selection of IT security topics including firewalls, encryption and malicious software. Based in UK.
http://www.security-forums.com/

SecurityRisk

Discussion forums on operating system, database and network security. Topics include security vulnerabilities, audit tools and white papers.
http://www.securityrisk.org/

Open CSO Project

Focused on career development in the security industry. Forums cover management and leadership skills, appropriate technical expertise as well as resources helpful to security professionals.
http://www.opencsoproject.org

Wilders Security Forums

Security forums covering a wide array of topics including spyware, viruses and privacy software.
http://www.wilderssecurity.com/

Castle Cops

Discussion forums. Subforums include firewalls, homeland security and specific security vendor products. Also offer software reviews and downloads.
http://castlecops.com/

TecBrain Support Forum

Forums covering security software, malware cleaning and vulnerabilities. Also has forums for non-security topics including website reviews, SEO and system support.
http://www.tecbrain.org/