Years before there was an Internet, radio understood the concept of click bait.

You put someone on the air saying the most bizarre things anyone can imagine, and if he or she does it in a voice that's loud and engaging enough, it will entertain some of the audience.

Over the years it's been a largely harmless phenomenon, with hosts like Art Bell talking about government conspiracies to cover up evidence of extraterrestrial landings here on Earth.

But it hasn't always been harmless, and these days, when mass media incorporates the omnipresent Internet, some of those click-bait voices are selling ideas way more disturbing than little green men.  
United States of Conspiracy, a PBS Frontline documentary that airs Tuesday at 10 p.m. ET (check local listings), focuses on the biggest name in the recent click-bait world, Alex Jones (top).

If you aren't a Jones fan, all you need to know is that he said the September 11 attack on the World Trade Center was perpetrated by the U.S. government to create a pretext for declaring martial law. 
Jones also said the Sandy Hook school massacre never happened, that it was staged by government-paid actors.

You get the idea.

Jim Gilmore, producer/director of United States of Conspiracy, suggests the real problem here is not that Jones is shouting this nonsense, since there have been nonsense-shouters back to the dawn of history.

The problem is that he got enough attention so that elements of his delusional babble were picked up by and incorporated into more legitimate enterprises like the presidential campaign of Donald Trump.

Trump would never repeat Jones's wildest assertions directly, of course. He hasn't personally gotten closer than promoting the false Obama "birther" movement. But Trump's associate and advisor Roger Stone (top) – the "good man" whose prison term was just commuted by Trump – has long been one of Jones's best media pals and frequent guests.

The connection is reflected, United States of Conspiracy suggests, in the way Trump echoes several key Jones points, notably that the media, the government and institutions like the FBI can't be trusted – that they are all, in effect, involved in a massive conspiracy to lie.

In the general sense, that's something that regular conservative radio and TV hosts have been saying for years. Jones just takes it to an extreme, like with his 9/11 scenario.

In terms of concrete consequences from Jones' claims, United States of Conspiracy interviews the parent of a murdered Sandy Hook 6-year-old. The parent has had to move multiple times and is now in semi-hiding to stay ahead of death threats from Jones followers.

United States of Conspiracy also asks the question that gets asked of all inflammatory hosts: Does Jones really believe this stuff, or has he simply found a product that sells?

The answer here isn't definitive, but this much is clear: Jones loves the life he's built from selling conspiracy theories, male enhancement pills, and body armor, so toning it down or even backtracking could be suicidal for his career and lifestyle.

Interviews with people who have known him, including those who worked on his show and his website, suggest he is unbothered that he encouraged the harassment of parents whose young children were murdered.

But United States of Conspiracy doesn't put everything on Jones. Besides noting how parts of his playbook have been incorporated by mainstream politicians, it points out that for many years Facebook, YouTube, and other social media platforms never questioned Jones' content, instead remaining quite content with all the clicks he brought them.

It also notes that whether Jones believes this stuff or not, hundreds of thousands of his followers do. In that sense, Jones' biggest contribution to their cause may not have been feeding them ideas, but providing the place for them to get together.

Like many programs before it, United States of Conspiracy suggests that the threat from Martians is far less troubling than the threat from some of our fellow Earthlings.