You know -- because anyone with access to social media knows -- that it was Obama’s secret hit squad of pillow-wielding assassins who took out Supreme Court Justice Antonin Scalia.

The timing of the “murder” seems a bit curious, so late in his second term that the president has little chance of getting a successor past the Senate. And, of course, Scalia was 79 years old with a history of serious heart problems. No matter. Rational thinking hardly keeps lunatic conspiracy theories like this from spreading through cyberspace like a brain-eating virus.

Speaking of which, apparently the Zika virus was spawned by an entomological experiment gone horribly wrong, after a British biotech company released genetically modified mosquitoes in a bungled attempt to control dengue fever.

The GMO Frankenbug theory was born last month on a post on popular social aggregator Reddit, saying, “mankind’s arrogance may have backfired on us,” and has since been disproved by reputable science writers. But too late. Sinister plans to spread Zika have now been attributed to, among other conspirators, Bill Gates and the Rockefeller Foundation. Or to a larvicide manufactured by Monsanto, though it turns out that Monsanto didn’t make the larvicide and that the larvicide can’t be linked to Zika. But what the hell?

This Zika plot has some kind of link to the old one-world-government thing. Though a counter theory roiling through the blogosphere holds that the Centers for Disease Control and Prevention invented the Zika sham just to scare us into submission (“The CDC is the medical CIA.”).

Nutty conspiracies are hardly new. When I was a kid, the John Birch Society was sure that fluoridated water was a communist plot. Then the investigation of the Kennedy assassination left enough troubling questions to spawn a thousand counter-theories.

But nowadays, the digital age can lend even a few disparate paranoids the sense that they are one of many. Even the craziest notions -- that George W. Bush plotted 9/11 and the Katrina floods, or that Obama invented Sandy Hook -- find community on Facebook or Reddit or Twitter or beyond.

I’ve noticed that James Tracy, the infamous conspiracy-theorist professor whom Florida Atlantic University finally fired last year, has added posts about Scalia and Zika to his netherworld blog. Tracy’s prevailing obsession remains that “Nobody died at Sandy Hook,” that the awful elementary school massacre was only theater, so many fake deaths contrived to allow Obama -- such a busy conspirator -- to confiscate our guns.

It’s getting crazier. Maybe even scarier. On Wednesday, the South Poverty Law Center released a report warning about the rise of “conspiracy-minded antigovernment ‘Patriot’ groups,” going from 874 in 2014 to 998 last year.

Conspiracy theories have become so prevalent on the Internet that mainstream news outlets now spend time and space debunking rumors we once would have ignored. In the past week, the Washington Post, New York Times, CNN, Fox News and other media deconstructed fantastic suppositions about Scalia’s death or the Zika virus.

Of course, out there in crazy land, the Times and Post and Miami Herald are all conspirators in the big secret plot.

By Fred Grimm

Fred Grimm writes for the Miami Herald. -- Ed.

(Tribune Content Agency)