One reason I can see a good use for smartphones, beside the usual

Simply put: the price of freedom is eternal vigilance. A smart phone is a valuable weapon in this.

The Seattle Pi story was, I think, the same as the one you saw somewhere else, snort, minutes apart - which is good, it's getting around the country, about the same guy anyway. I remember it as well written.

The smartphone thing was something I pushed in my title because there is some backlash to them reccently, how people can hardly walk down the street these days because other people aren't watching where they are going. Now those phones are sounding smart again in another way.

I gave up my addiction to cell phones eight years ago. I may have to get a smart phone specifically to be a citizen witness.

I've kept my old dumb one mainly to have in case of car breakdown (triple A to the rescue) or some weird medical need (never happens but y'never know).

I'm an old photographer, not a pro, but avid for decades, and have taken hundreds of street photos. I have enough of those now, am busy enough trying to organize the ones I have, as I still like the prints. We'll see - I may switch cell phones one of these days, and that would be a fair part of the reason.

I carry an older iPhone, but prefer the old flip phones. There are alternatives to taking good video. I had a Go Pro for a while, but gave it to my son. It was too large for street use. I wanted to be less obvious but not secretive. There are smaller 720 or 1080p dedicated video rigs that are the size of a thumb drive. As far as dealing with the authorities and street video, it can get very dicey. There is no consistency in the education of police and their interpretation of said laws. There are many great articles in Photographic journals and magazines about our rights as street photogs. But I never push the point. My equipment and my knees are too valuable. (pushed to ground once covering an event) The World appears a bit more aggressive now than it was twenty years ago. Having said that, I recall 1968 in Chicago, Kent State, 1964 Alabama...etc. Maybe we just see more of the aggression that was always there. Photographers of any level seem to give us some perspective in a situation or event. More cameras out there is probably a good thing in the long run. As long as all the video is seen and any editing is for technical reasons not to slant the coverage.

This why we need to witness, no one else will:

If All Movies Had Cell Phones :
It's a nine year old video with really outdated phones but it still hits home.

Lots of workers use their phone cameras to prove how well their job went or didn't went.