Here's Laura Mather's own answer to an interview question she poses to job applicants at her website security firm (which works with ING Direct and StubHub, among others). Silver Tail Systems uniquely maps all users' behavior at a site--then spots the crooks.
To do that, Mather needs a team that can think like the bad guys. "Before I meet a prospective new client, I essentially do what criminals would do," she says. When she unveils how she and her team could unhinge a prospect's site, "people usually say, ‘Wow, yeah, we need what you have.' "