facebook, napster, spotify.he's bringing his silicon valley smarts to something even bolder -- curing cancer. call it the ultimate computer hack. keith morrison reports from california. >> right here, beautiful. >> it's a chilly spring evening in bel air, california. too chilly for this sort of thing, quite frankly. yet this flashy ritual is perhaps the most ordinary thing about the remarkable doings just outside his back door. >> i don't even feel like i'm in my backyard. it's the weirdest feeling. >> his name is sean parker and this is indeed his backyard, in which he's built a giant glass atrium for his dinner guests who will be entertained by the likes of lady gaga, all to announce -- >> a manhattan project for curing cancer with the immune system. >> billionaires, think they can do anything. >> what in heaven's name possessed you to think that you could wade into a field where the world's great medical minds have been working so hard for so long and make a big difference? >> you're talking to somebody as an

at 19 he and an internet buddy named sean fanning created napster.ng service that up ended the recording industry. >> we were troubled kids that weren't totally happy with the life we were living and we were incredibly curious. >> and now he is rich. book made him a billionaire and then he helped unleash spotify and at 36 he is husband of alexandra, father of 2, and the proud owner of one of l.a.'s most expensive and iconic mid century mansions. >> the architecture is modern. >> but curious kid, yes that he most certainly still is. so when his good friend the hollywood producer was fighting cancer he got curious about a cutting edge treatment called immunotherapy. >> she participated in early clinical trials around immunotherapy which had it been maybe two years later -- >> maybe. >> perhaps it would have worked. >> but it didn't. even though it seemed so promising. >> you know losing laura changed me. i went from being someone for whom this was an abstract problem to a militant activist. >> it harnesses the body's immune system and equips it to atta

. >> sean parker of facebook and napster. >> what in heaven's name possessed you? >> maybe a hacker. >> a computer hack. >> killer t cells like little commuters. >> a revolutionary therapy saving lives like hers. >> i found i was cancer free. >> reborn? >> yes, reborn. i think this billionaire is on to something. >>> but first, richard engel with an nbc exclusive. >> i let my family down. i let my nation down. >> why should i believe you? >> he's the young american that went from the ivy league to isis. >> he asked to help isis bring down planes. >> why did he join, and why did he return? >> they got more brutal and brutal. >> you saw heads on a stick? >> yeah. >> tonight, a dark journey inside isis. >> you see madness in thei >> that story right now "on assignment." >>> good evening and welcome to "on assignment." i'm lester holt. tonight we take you into the very heart of the terrorist world and for the first time, an american who joined isis in syria has returned to reveal the inr working of the terrorist group. he told his story exclusively to richard ingle. fo

>> the music industry got after and the with napster and internet piracy. then it got whipsawed.he consumer has spoken. they want streaming and total access to everything, which is what my company cure music is doing. we are giving access at a new price point, $1.99. there is on demand streaming in is pandora-like radio and unbelieve social features. because as we say, social-plus music equals fun. and that's a big part of what has been missing. kennedy: google buys that for a ton money. i there room in the marketplace for another streaming service. you have spotify, i heart radio, apple. >> i came out of retirement because i think this company has up a unique approach to it. it was built with the idea that social and streaming were going to play equal parts. you can stream your music and demand. you can send your 8 favorite congresses to your friend. they can send them back to you. you can send video with it. pictures. >> the fee is so low and you are paying licensing fees for their music, either you aren't going to make any money or the artists aren't going to make any money. >

our economy will wake from its napster, take off like a white bronco, as they cut our taxes like lorenat, and crush our enemies like nancy kerrigan's knees. (applause) >> stephen: mm-hmm. so pay no attention to the spin doctors and their "yada yada" - the clintons will double-dare to be our friends because family matters, and together, they will lead us into the next willenium. (cheers and applause) with announcements like this, hilary's campaign might just be saved by the bill, as long as he never has to say "oops, i did it again." (laughter) of course, there was another big vote this weekend: eurovision. thank you, europeans. (cheers and applause) eurovision is a no-holds-barred musical throwdown where european countries compete to see who can write the best pop song. it's the biggest europe-wide contest since the 14th century's "so you think you can black plague." (laughter) no one won that one. (laughter) the countries are judged on the performance of their signature song. it's called "eurovision" -- "euro", meaning "europe" and "vision," meaning "sound". (laughter) i imagine why it

the coalition is backed by gavin newsom, includes exfacebook and napster co-founder sean parker, whodonated more than a million dollars to the campaign. this morning i checked, the department of revenue in colorado, where recreational marijuana use is legal t. state raised more than $7 million in the fiscal 2014, 2015 year, for this fiscal year in february, that figure is almost $112 million. there is opposition, like the california police chiefs association which says there is a concern of high addiction rates, also a national group like citizens against legalizing marijuana, which points to studies like one out of uc davis in march that said regular users had more debts and cash flow problems as well as downward social mobile. so there is set to be a debate here. maybe in california. if voters do pass this, california would become the fifth state in the country to legalize recreational use of marijuana. >> thank you. >>> an alameda police officer and two others were hurt in a crash overnight t. police cruiser and the toyota crashed last night at lincoln and fifth streets. police sa

whether it's itunes, napster, whatever the issue de jure is. right now, it's cord cutting. okay, fine. these are still people that are going to want to watch "frozen," still people that are going to want to watch spider-man films, "star wars" films. they will find a way to get people watching espn in a way that's profitable for the company. >> cable networks are 28% of operating profit. that's obviously been where the bulk of the concern has lied. >> sure. >> on august the 4th, disney shares were at 121 bucks. iger says the thing about espn, the world loses its mind. the stock goes down to 110. that's where it was on august 5th. today, it's working its way back to 106. is it a buy here? >> i think it is. i absolutely think it is. i look at this name and think, it's an overreaction in the cord cutting. i think it's also an overreaction in the other thing that actually has had some pressure on the stock is, this whole idea of who's going to be stepping in when eisner is going to step down. >> iger. >> iger, excuse me. i'm going back a little bit. >> freudian slip. but when ig