. >>> you may not know the name sean parker, but you sure know what he's been a part of.book, napster, spotify. now 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'

>> this is how most people were introduced to sean parker.edy arrogant party boy by justin timberlake in the social network. >> the thing that hurts the most is when someone's only impression of me comes from having watched that film and they have preconceived notions about who i am. all of which are completely wrong. >> what's right? well he was the first president of facebook and he certainly has been disruptive. in high school he got into trouble with the fbi for illegal hacking. at 19 he and an internet buddy named sean fanning created napster. the music sharing 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

. >> 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

gavin newsom and former facebook president sean parker. even some local congressmen. we will have a live report on this story coming up in about an hour. >>> the city of santa clara might be the 49ers newest opponent. the team announced it is taking legal action. the 9ers want to slash the rent for levy stadium. >> the 49ers have been paying the city of santa clara 25 million in rent per year t. 9ers are proposeing a new rent of $19 million a year him team claims better than expected stadium revenue allows them under the agreement with the stadium authority to renegotiate their rent. but so far, neither side is backing down. so the 9ers are sending this case to arbitration. >>> no comment yet from the city of santa clara, but a former high ranking 49ers exec is speaking out to nbc bay area. this former team executive, who wished to remain anonymous tells us, quote the 49ers are technically correct in invoking a rental reduction, but the way they're doing it is petty wise and pound foolish. the york family is swimming in profits, close quote. forbes magazine ranks the

it is sported by gavin newsom and former facebook president sean parker among others. we will have a live report coming up if about an hour. >>> the city of santa clara might be the 49ers newest opponent. the team announced it is tekeing legal action. they want them to pay the city $24.5 in rent per year t. 9ers are proposing a new rent of $19 million a year. the team claims better than expected revenue allows them under the agreement to renegotiate their rent. so far, neither side is backing down. so the 9ers are sending this case to arbitration. all right. let's talk a little basketball this morning. what a night for warriors and their fans. some of the fans might be a little tired this morning. >> raise your hand if you are tired. it didn't look good to start. the finish is what matters, coming back from a double digit deficit to win game two against portland. for three-quarters, the trail blazers really dominated this game. but in the fourth quarter the warriors outscored the blazers by 22 points to win 110 to 99. clay thompson ends up with 27 points as the doves t

sean parker donated $1 million to this measure. some have taken to calling it the parker initiative.>> to have any kind of idea right now what kind of support there is for this initiative ? >> reporter: the most recent poor i could find was done last year. it showed 85% of likely voters in california support this measure. that is a slight majority.>> you talked about 2010, 53% of those who voted said no way. they do not want to legalize this. why all of a sudden are they still confident that something will change with voters when they go to the polls in november ? >> reporter: keep in mind, last time in 2010 with this measure failed, it was polling in favor before. now it is polling 55% as i said. supporters are hoping that the legalization on these other states will bode well for this measure here in november. track we are ready more today about the final hours of prince's life and his connection to a marion county drug addiction dr., dr. howard kornfeld. his attorney said that princes representative asked him to see the musician.

you think it's sean parker who said if you don't do something nobody will. >> i asked the question inld tell you he cited -- when i spoke with him he talked about some of the stories you wrote about sean parker. >> we wrote a story about how the tenth street in manhattan where he lived had been dug up because of a fios connection going to his house, his neighbors complained. was that the piece that pushed him over the edge? we ran stories about his wedding. the damage to the red woods, the fine he got for damage to the redwoo redwoods. was that the piece that pushed him over the edge? >> how about the parties in davos? >> are you on your own jihad to any extent against him, which is to say he has connections to facebook. gawker has a relationship with facebook. >> everybody has a relationship with facebook. >> you are one of a handful of media organizations involved with the facebook live where they're paying gawker. >> peter thiel does not believe gawker is a legitimate media organization. but the company, the giant company that controls pretty much distribution of news in the modern

gavin newsom and sean parker, who by the way donated more than a million dollars to the campaign supportershecked this effort. i checked in colorado, where recreational use is illegal t. state raised $7 million in the fiscal year and already for this fess cal year through march, that something is almost $112 million. this is opposition, like the california police chiefs association, which here in california which says there are concerns of high addiction rates and legalizing marijuana, which points to studies, like this march that said regular users ahood more debt and cash flow problems. they consider it a scheduled i illegal drug. the tide seals to be turning state by state. according to ballot pedia as of today, there are 16 states that could have a pot legalization measure on the ballot this year again. live here in san francisco, "today in the bay." >> thank you very much, that's a state wide measure. it appears that san francisco voters are going to decide whether or not 16 and 17-year-olds have the right to vote. supervisors will make the final decision to put it on the november ball

>> well, i don't think it's a unique idea to sean parker. it be great to have it in your home. there's a lot of reasons why it doesn't happen right away. but i'm glad and happy to see the push to try to make it happen because i think it's something consumers would love even if it's a slightly higher price point, then you have a choice. at the same time movie theaters are a huge part of the success of hollywood and we have to respect that and find that perfect balance. and these conversations are just helping progress that. so in that way it's a very good thing. i would say as you mentioned the change, you look at another benefit is consumer products. it's not just digital products but also all those brands we don't have the scale internationally just with our own product maybe dreamworks doesn't either, together along with universal maybe we have a much better consumer products opportunity as well digitally and in part goods. >> very interesting time to watch that acquisition. and i know your nbc up front is happening today. >> it's an excit