so, you've issued this warning, cert certainly, about misinformation. what do you make of this news? >> well, i think it reinforces what we've known for a long time, that there is a lot of misinformation circulating on these sites. i will readily say that the sites have recognized that this is a challenge, and they've stepped up to do some things to reduce the spread of misinformation. and i credit them for that. but it's not nearly enough, because there is still a tremendous amount of misinformation circulating. people who are super spreaders of misinformation are continuing to put out inaccurate information online. and there are algorithms that continue to serve up more and more misinformation to people who encounter it the first time. these are things that companies can and must change and they have a responsibility to do so quickly and transparently. >> dr. murthy, thank you so much for being with us this morning on "state of the union." >> of course. thanks, brianna. good to speak with you again. he chose the truth over