A year ago, James Robinson played a trick on about 600 salespeople at a company where you wouldn't expect the employees to be easily fooled. Staffers at Websense Inc. got a generic-looking e-mail that encouraged them to click on a link to learn which product they could sell to earn a bigger bonus. The link led to an unfamiliar website that asked for their user names and passwords. "What came back to us was crazy, it was in the 60 to 70 percentile -- people were clicking on the link," said Robinson, security architecture and strategy officer at the San Diego-based company. Of those who clicked, 80 percent proceeded to obediently type in their log-in credentials, which is the kind of information that could allow a hacker to break into a corporate network and steal critical data.Even more alarming? These folks sell cyber-security products for a living.