Steyer has four children — three teenagers and a 6-year-old he and his wife adopted several years ago. And having a dad who has definitive views about media can be from the kids' view, a bummer.
"My kids tell me, 'Dad, you're our worst nightmare. We go to our friends' houses, and their parents tell us we can't watch this movie or play that game because you said it's not OK. It's so embarrassing.' Then I laugh. Their friends know what I do, and it makes them think," Steyer said.
He latched on to video game violence five years ago, when he asked the children he was tutoring in East Palo Alto what they were doing at home instead of reading. The answer: playing Grand Theft Auto III: San Andreas, a video game in which players could hijack cars and attack police officers.
"These kids knew how to play Grand Theft Auto before they could read," Steyer said.
He has three beefs with violent games.
"It makes kids more aggressive, it desensitizes them to real world violence and it makes kids scared," he said. "The public health impacts on children are clear to me."
Steyer linked up with Leland Yee, a psychologist who as a California state assemblyman drafted the controversial video game legislation that was signed into law by Gov. Arnold Schwarzenegger in 2005. (Yee, a Democrat, is now a state senator from San Francisco.)
Although his relentless championing of the law puts him in direct conflict with the game industry, Steyer insists he's not an anti-game zealot.
"We're not enemies of video games at all," he said. "We believe strongly that games are a form of digital literacy. Games are potentially great teaching tools. If we think it's good for kids, we promote it. If we don't, we call it out."
By modeling his group as a "Consumer Reports for media," Steyer has been able to attract far more allies than enemies.
"Anyone who has kids understands the need for what his organization does," said Goldman Sachs' Sykes, who attended business school at Stanford when Steyer was at the law school in the early 1980s. "It's a very appealing and winning argument."
Sykes introduced Steyer to a number of his investment banking clients, including Time Warner Cable Inc., DirecTV and Comcast Corp. All now pay Common Sense Media for the right to distribute the group's reviews and videos to their cable subscribers via their on-demand services, as does Tribune Media Services, whose parent Tribune Co. owns the Los Angeles Times.
Steyer's organization received roughly half of its $8 million in revenue in 2009 from licensing its content. The other half comes from contributions from foundations such as the Omidyar Network Fund, the John D. and Catherine T. MacArthur Foundation, the Sherwood Foundation, and the William and Flora Hewlett Foundation.
Donations also come from its board of directors, which include Steyer's younger brother Tom, who made the Forbes list of billionaires in 2008 with an estimated net worth of $1.2 billion. Tom Steyer made his fortune in finance, founding Farralon Capital Management, an investment firm for the ultra-wealthy.
"Jim is wound up," his brother said. "If you want to just sit there and relax, it's not going to happen with him. A lot of people find that really annoying. He's a huge pain, but a big protector."