What was the last thing you watched on Youtube?

I use it to browse for movie trailers, to track down “lost” concert performances, archived moments of history, condensed versions of college basketball games, famous bits of sports history.

An obscure song I’ve caught a snippet of in a movie? To Youtube I go.

But every now and then Youtube makes news. Sometimes it’s for some “Youtuber” who got rich making funny videos, pulling pranks or showing off a particularly telegenic child or dog.

More often, though, it’s because of some unpleasant, unfair and even democracy/public-health threatening policy of Youtube and its behemoth parent company, Alphabet, the umbrella name for all the tentacles in Google’s omnipotent presence on the Internet.

Some of us can regard the streaming video archive as home to a “community” or two that we might consider ourselves a part of. Most of us don’t think of Youtube as a primary source for “news,” and might fret about the millions of those Millennial-age-and-younger who do.

But you might be kept up at nights worrying about just that statistical fact after watching “The Youtube Effect,” a deep dive documentary that covers the history of its birth, its utility and value in entertainment and news-spreading terms. The latest film from Alex Winter (“The Panama Papers,” “Trust Machine: The Story of Blockchain” and “Zappa“) also exposes the downside to letting so much of what we know, believe and value be determined by blind, amoral algorithms and the unresponsive and mostly unaccountable corporate behemoth that imposes them on us.

A Youtube founder, a former CEO, journalists, academics, “Youtubers” and victims of the policies of this valuable, wildly popular and profitable website/digital archive sing its praises and herald its possibilities. And most of them also point to excesses, inhumane policies and the fearsome power of this prone-to-abuse near-monopoly.

It began in the mid-2000s as a modest enterprise and a place one could go to find Chinese college kids lip-synching to The Backstreet Boys or cats and dogs and kids doing cute things.

The former CEO, Susan Wojcicki, marveled at the realization that “people want to see other people like them” would be the key to the site’s explosive growth, and championed Google purchasing Youtube for $1.65 billion within a year of its 2005 launch.

In those heady days of social media companies evolving into Media Companies, Google, Facebook, Twitter and the rest quickly figured out the business model — offering your service for “free,” “extracting data” from you every time you use their site, and “selling ads” to you as they did, notes U-C Berkeley’s Hany Farid.

Youtubers such as the the early-adapters at Smosh and Contrapoints transgender activist, interviewer and entertainer Natalie Wynn marvel at becoming overnight successes, wealthy Youtube entrepreneurs.

And then Caleb Cain, onetime Youtube fanatic, tells his story of how Youtube’s algorithm-driven “rabbit holes” radicalized him and “could radicalize anyone” thanks to machine-learning that has the site feed devotees more and more arresting “echo chamber” videos that reinforce via a downward spiral of twisted misinformation that feed a viewer’s darkest prejudices and urges.

It’s alarming. Youtube, as Winter’s film points out, played a big role in protests such as Occupy Wall Street and the Egyptian uprising during The Arab Spring. Youtube made the George Floyd murder-by-cop story an international cause.

But it also fed the delusions of mass shooters in America, New Zealand and elsewhere, many of them posting videos about what they aimed to do and where on Youtube they were inspired to do it.

Youtube was also linked to performative violence aimed at a Q-Anon targeted pizza parlour and played a major role in helping like-minded fascists organize and carry out the January 6 assault on the United States Capital.

It is, Profossor Farid notes, ground zero of a “misinformation apocalypse,” something that came to a head during the Trump administration and its war on objective truth and reality, which blew up in everyone’s faces when the COVID pandemic exploded and actual medical and science profesionals found themselves under assault from screaming clickbait tantrum tossers and self-appointed “experts” on Youtube.

Winter, best known as “Bill” from the “Bill and Ted” movies, has become a documentary filmmaker of great repute, quite adept at explaining complex scandals (“The Panama Papers”), economic tech (“The Story of Blockchain”) and people (“Zappa”). This is his best doc yet.

He first lays out the miracle that is Youtube, getting at its appeal via montages of K-Pop, puppies and protests. His interview subjects then ennumerate the problems that have come with a seriously under-regulated media near-monopoly, and some of those intervewees even dare to state the obvious.

“Corporations don’t do the right thing unil they’re forced to,” and with Google spending NRA money to buy influence in Congress, their all-profit/no-accountability business model isn’t going anywhere.

And then we meet Andy Parker, the father of a Roanoke, Va. TV reporter murdered, with her videographer, live on air. Parker started a one-person crusade to try and force Google/Youtube to take down the scores of copies of that live feed, replaying his daughter’s murder ad nauseum for the curious, the callous and the perverse. For profit, complete with ads.

No, one person can’t jar an insensate media empire into changing its ways. But millions of them, voting for legislators just as alarmed as the rest of us by how much undeserved and poorly-policed power has been concentrated in a few hands, just might.

Rating: unrated, scenes of street violence, some profanity

Cast: Susan Wojcicki, Caleb Cain, Natalie Wynn, Steve Chen, Talia Lavin, Jillian C. York, Briana Wu and Andy Parker

Credits: Scripted and directed by Alex Winter. A Drafthouse Films release.

Running time: 1:39