Of all the security clubs and associations, the one that impresses me most is FIRST, the Forum for Incident Response and Security Teams. Why? Because it's focused, born out of real business requirements and it's highly selective, i.e. you have to be sponsored and audited to gain membership. FIRST is not a club that exists to make an income for its organizers. It's an international community that serves a real purpose: helping Government, Industry and Academia to respond quickly and effectively to new security threats. So I have no hesitation in recommending that you book a space in your busy diary to attend their Annual Conference in Seville in June. Even if you can't make it, I'd recommend you check out the excellent Global Security News feed on their Web site, which must rank as one most comprehensive sources of up-to-date security information.
