From the growing number of parents who refuse to vaccinate their children to the belief that state education standards are part of an anti-Christian communist plot, conspiracy theories keep popping up across the country. These fictions and fears are creating public health risks, blocking government policies and even hurting the economy, reports Kurt Eichenwald in Newsweek.

According to experts, the influence and reach of conspiracy theories is growing largely due to almost effortless communication. Stories, ideas and far-fetched speculation can easily be shared by users of social media, each member adding his or her own take, untethered by fact.

“Conspiracy narratives are more common in public discourse than they were previously,’’ said Eric Oliver, a professor of political science at the University of Chicago who has published research on the phenomenon. “We seem to have crossed a threshold.”

Agenda 21 remains one of the most well-known government conspiracy theories of the past few decades. Born out of a 1992 nonbinding agreement between President George H.W. Bush and 177 other world leaders, Agenda 21 was initially an attempt for countries to share their interest in ensuring that urban development and land-use projects didn't destroy the environment.

During its inception, political leaders across all parties had no major concerns about the idea. But extremist organizations soon labeled Agenda 21 as the U.N.'s attempt to take private property, push a communist ideology and silence opposition. The document was knocked by the Republican National Committee in 2012 and talk of Agenda 21's dangers continues to resonate. Many local governments have joined the movement against Agenda 21, citing their suspicions as a reason to abandon economic development plans such as high-speed rail in Florida and even the building of bike paths.

“These kinds of theories have the effect of completely distorting any rational discussion we can have in this country,’’ said Mark Potok, a senior fellow at the Southern Poverty Law Center who wrote a report on the impact of the Agenda 21 conspiracy. “They are having a real impact now.”

Read the full story here: http://www.newsweek.com/2014/05/23/plots-destroy-america-251123.html