When social media was still shiny and new, it was mostly viewed through rose-coloured glasses.

But many are seeing it more clearly since reports of meddling in the 2016 American presidential election revealed that many Facebook users' data was mined to sway their votes.

A new documentary, The Great Hack, recounts this story with a convincing urgency that may give you pause before you click "yes" on yet another online user agreement without reading it.

Another documentary, the series Diagnosis, appears headed in the opposite direction, evoking the optimism of the digital age by showing how the Web can be used for good - in this case, to crowdsource solutions to medical problems that leave doctors baffled and patients despondent.

Yet the common thread running through these titles is the value of questioning authority and knowing that information can both empower and disempower.

Based on a New York Times column by Dr Lisa Sanders, Diagnosis - by turns heartbreaking and uplifting - looks at cases that the writer, a medical doctor and former consultant on the television drama House (2004 to 2012), shared with her readers so they could help solve mystery illnesses that had stumped all medical experts consulted.

There is a young woman with crippling muscle pain that left her doctors scratching their heads, though some sued her for unpaid medical bills anyway.

And there is a little girl with unexplained epileptic seizures whose only option seemed to be a debilitating surgery.

In these and other instances, the wisdom of the crowd - medical professionals and ordinary folk who had encountered similar symptoms - helped the patients find better outcomes than what they had been asked to settle for.

In others, there was no solution per se, but the offer of a community of sympathetic souls.

The bigger question, though, is why the medical system fails these people.

As Dr Sanders observes, most doctors focus on managing symptoms and avoiding death - but chronic health problems require knowing why conditions occur, "which is the kind of thinking that happens outside hospitals".

Sometimes the answer is staring doctors in the face, but as one neurologist suggests, "everyone has their anchoring biases" and can miss something.

It can be dangerous, of course, to ignore some medical advice - the anti-vaccination movement comes to mind here.

But these extreme case studies eloquently illustrate the benefits - and occasionally even the necessity - of not accepting the status quo.

The Great Hack details the scandal surrounding Cambridge Analytica, the British data-mining and consulting firm that may have helped elect Mr Donald Trump as President of the United States and nudged Britons to vote for Brexit through fear-mongering and misinformation.

Those idiotic Facebook quizzes and personality tests? That was one way it collected the data of users and their friends and built psychological profiles of voters in swing states.

The narrative follows a legal challenge mounted by an American academic, Professor David Carroll. Appalled by how much data everyone is unwittingly haemorrhaging, he pressed for companies who had mined his data to tell him what they had, how they got it and what they had used it for.

Prof Carroll and two former Cambridge Analytica employees-turned-whistleblowers shine a harsh light on what users give up in exchange for free connectivity, and how that information can be used to manipulate people.

One whistleblower described the company as a "full-service propaganda machine" that was hired to meddle in elections everywhere from Malaysia to Trinidad.

Data has now surpassed oil as the most valuable asset on earth, and such is the power of big data and these psychometric technologies that the British government prohibits their export because they are considered weapons.

All of which is sobering and you would hope it makes viewers think twice about not insisting on better data protections and rights.

Yet, the sinking feeling is that most will merely be briefly outraged before continuing as they have and that is where the film can be found wanting.

Apart from cursorily suggesting self-monetising your data rights as you would property rights, there is no prescription or call to action.

As Prof Carroll says, people do not generally want to admit propaganda works because it means confronting their own susceptibilities and over-reliance on these technologies.

This rings true - but is profoundly unhelpful.