John Tan joined the L0pht in 1996 contributing to the Full Disclosure movement with an advisory on Novell Netware 3.x. He was part of the L0pht's 1998 US Senate Testimony and published a widely cited essay called CyberUL which pointed out the conflict of interest that exists with the still current model of security certifications for people and products. He has over 20 years experience within the Financial industry and most recently shifted his focus to Health Insurance.