we've worked with who have been exploited online talk about craigslist. craigslist is like the walmart of online sex trafficking. >> reporter: so we're here at george washington university and we just found out that craig newmark, founder of craigslist is going to be speaking here at a tech conference, he doesn't know we're coming. he's been media shy lately about all of these allegations against him. this guy is the craig in craigslist. it's his list. so can people trust that children are not being sex trafficked on craigslist? >> i think we explained that pretty thoroughly on our blog. >> that's where jim buckmaster says that you will immediately contact law enforcement if you suspect anything suspicious? >> yes, jim does a great job showing that we do more than anyone in this area, pretty good for a community of 50 million people. >> this is inspector brian bray with the d.c. metropolitan police department, also in charge of the prostitution enforcement unit in craigslist blog they say they'll immediately contact law enforcement any time they see a