I'm not interested in a "Free market" in its purest form. The first thing that comes to mind is the food industry. Look at the crap being allowed into our food with regulations. Could you imagine what companies (for the sake of a dollar) would put into our food if there weren't any regulations? Are you a label reader? Guess what? How many companies would put the ingredients on their product if they weren't made to? My guess is zero. Russian roulette anyone?
How many companies do you really think would put potentially harmful ingredients into their food products if, without the protection of the FDA's "considered safe for human consumption" policy, they knew that the first time any of those ingredients were actually linked to some sort of health risk the ensuing class-action lawsuit would put them out of business?
One of the biggest problems with regulations is the resulting limiting of liability. When the risk/reward comparison is simply x amount of dollars in profit vs a maximum of x amount of dollars in potential lawsuits where the burden of proof is on the consumer, companies are far more likely to take those risks than when it is x amount of dollars in profit vs an unlimited amount of dollars in potential lawsuits where the burden of proof is on the company.