, craig newmark, the founder of craigslist, the online site that in less than two decades hasd classified advertising. and has made craig a very wealthy man, and he boasts of using technology for the public good. >> i've been encountered by brian ross for abc news. >> reporter: when we showed up to ask him about allegations that his craigslist might actually be harming the public good, he refused to answer our questions. how do you respond to that? >> brian, how have you been doing? it's been a long time since we've spoken. >> reporter: this is what craig newmark did not want to talk about with "20/20." the bumbo baby booster seats recalled for safety defects, but still for sale on craigslist. the recalled wooden storage chests that can trap children inside, still for sale on craigslist. the recalled dishwashers that can burst into flames, for sale on craigslist. all despite pleas from the government to do what others do to block their sales. >> they do not and will not do it to date. >> reporter: and what do you say about that? >> i think it's morally irresponsible. >> report

craig himself. >> reporter: mr. newmark, brian ross, abc. how are you? this is craig newmark, the founder of craigslist, under fire today for allowing the sale of potentially dangerous products under official safety recall. something he did not want to talk about. >> i've been encountered by brian ross for abc news. >> reporter: it is illegal to sell a recalled product, but an abc news undercover investigation found a wide range of them for sale on craigslist. including the recalled version of the bumbo baby seat. recalled dehumidifiers and that can catch on fire. and recalled wooden chests that can trap children inside. >> i live every day in fear of that happening to my children. >> reporter: the new chairman of the consumer product safety commission, elliott kaye, says craigslist refuses to do what amazon and ebay do to block the sale of dangerous recalled items. >> they do not and will not do it to date. >> reporter: and what do you say about that? >> i think it's morally irresponsible. >> reporter: craigslist says it has an automated system to help

the founder is craig newmark and would not answer our questions, when we caught up with him, saying he'scountered from brian ross from abc news. >> reporter: told the site is founded is accused of being morally irresponsible, putting children's lives at risk, he walked away. we want your answers and your side of the story. isn't it possible? >> good to meet you. >> reporter: you don't want to speak about these allegations at all? there are more than 400 recalls issued every year for safety defects. most are not well-publicized and unnoticed. they end up undetected in the homes of american families and on sites like craigslist. >> it's like the wild west. no way to police. >> people are trying to save money, so they turn to craigslist to get some of those cheaper costs. >> never do anything bad, brian ross will come get you. >> he starts with a handshake. it's downhill from there. >> there are important questions to be answered. >> really helping. quite surprising. and you can see more of brian's report tonight on "20/20," right here on abc. and to find out if your household products are