>> have you ever drawn the line an elling data to advertiser? mark: yes, senator, we don't sell data at all. he way the ad system works, advertisers can come to us and ay i have a message that i'm trying to reach a certain type of people that might be they sted in something, might live in a place and we help them get that message in front of people. this is one of the widely mischararacterized about our we sell data and it's actually one of the most important parts of how facebook data.we don't sell advertisers do not get access to people's individual data. >> have you ever collected the content of phone calls or essages through any facebook application or service? mark: senator, i don't believe the ve ever collected content of phone calls. messenger app called that allows people to message most of their facebook friends. on the android operating system allow people to use that as their client for both facebook messages and text, so we do allow people to import their texts into that. >> let me ask you about government surveillance. years, faceboo

in the we have created the opioid fraud, abuse and detection network, which is a data ell within theem w existing computer systems of the drug enforcement administration so we can easily determine the position pharmacies and other distributors are moving prescription drugs. are extraordinary outliers. they give us indications of where fraud and abuse is occurring. target packages have been sent out to investigators and arrests have been made. one united states attorney said, i did not think much about it, but when you look at it there were six professionals in pittsburgh and every one were on this list. that may need --that made me a believer. we sent experienced attorneys to hotspots around the country to focus on that. we indicted chinese nationals for the first time on fentanyl charges. that is coming from china and mexico directly through the mail. we have established a new program called j-code, the fbi program with dea to identify through the dark net and purchase undercover drugs in that way and to target that group. we announce the criminal prescription and litigation task forc