From an April 18, 2011 article in The Daily Caller by Matthew Boyle:

A number of conservative activists and bloggers say they’re furious at media magnate Glenn Beck for what they call content theft. Over the past several years, Beck has relied on video, audio and written content from others to fill his radio and television shows, as well as his websites. Often he has credited his fellow conservatives for their work. Yet in many other instances say dozens of conservative journalists who spoke to The Daily Caller, he has not, often taking elaborate steps to cloak the origins of the material.

Publisher Andrew Breitbart has seen a number of his stories surface on various Beck media properties over the past few years. While he describes himself as “grateful for the many times he has credited me and my sites,” Breitbart says that “sometimes he also uses other peoples’ work without crediting them, making it appear as though it were his own. But especially since adopting ‘The Truth Has No Agenda’ slogan – and trying to deliberately re-position himself as the pious conscience and judge of many of those he took content from – he has exposed himself to his new motto’s unforgiving standard.”

By any standard, Beck seems unusually reliant on the work of others, and unusually reluctant to credit it. In an interview with TheDC, Roger L. Simon, CEO of Pajamas Media, suggested that Beck has committed the journalistic equivalent of a notorious crime. “It is not a question of just doing it right the majority of the time. It is a question of doing it right always,” Simon said. “Doris Kearns Goodwin is forever a fraud in my estimation because she has been caught plagiarizing once. If you rob a bank once, you still robbed a bank.”

A remarkably large number of conservative writers say they feel robbed.

[...]

In February of this year, Beck announced on the radio that he had created a new motto for his website, The Blaze. “This is the slogan that I wrote for The Blaze,” Beck said. “We’ve put it up everywhere here and we’ve written it out for The Blaze. And it is: ‘The truth has no agenda.’”

But in fact, this was not the truth. Beck did not write any such slogan for The Blaze. According to GoDaddy.com website domain name registration records, a man named Michael Opelka bought the domain “truthhasnoagenda.com” in July 2009. Beck has since hired Opelka to work for The Blaze. Shortly thereafter, Beck began selling “The Truth Has No Agenda” merchandise.

Beck’s reputation as an ungenerous user of other people’s work has occasionally surfaced in public. Conservative radio host Mark Levin recently took aim at Beck, whom he refers to as the “5-PMer,” this way: “You won’t find me putting my name on books that other people write. You’ll never find me doing that,” Levin said. “I would never, ever preach to you about principles and viewpoints that I am incapable of writing about. Never.”

The article details many examples of Beck allegedly lifting other people’s work without attribution. These allegations are unsurprising.