Glenn Beck is a cable-news phenomenon. His hour-long program on Fox News Channel routinely attracts more viewers than all of its competitors in the five p.m. time slot combined, sometimes reaching as many as 3.5 million people. Fox News, however, hasn't been able to translate those huge audience numbers into premium advertisers on Beck's show.

The reason for this paradox is Beck's perpetual proximity to controversy. His hard-core fans may cheer when the blackboard-wielding bloviator calls President Obama "a racist,"� dismisses Senator Mary Landrieu (D-LA) as "a high-class prostitute,"� or blames the Anti-Defamation League for the "plight of the Jewish people." But such talk tends to unnerve advertisers seeking the broadest possible audience for their products.

Still, Beck would probably not have lost scores of potential advertisers were it not for the activities of a third-year law student at the University of Wisconsin named Angelo Carusone.

The black-haired, sharp-featured Carusone, a 28-year-old Long Island native and politics junkie, had been bothered by Beck for years, but he reached his breaking point on June 30, 2009, when Beck nodded along while his guest, former C.I.A. agent Michael Scheuer, declared that "the only chance we have as a country right now is" � for bin Laden to "detonate a major weapon"� in the U.S. Carusone figured that engaging in a war of words with the combative Beck would be to play into his hands, so he opted for a different approach: He would target the show's advertisers and see if he could shame them into pulling their sponsorship dollars.

His method is simple enough. Working from an office in his two-bedroom apartment in Madison, Wisconsin, which he shares with Brett Abrams, his partner of six years, Carusone ingests a super-size dose of Glenn Beck every day--three hours of syndicated radio programming and one hour on Fox News. "It would be incredibly unfair of me to charge Beck with all of these claims if I didn't get everything he says exactly right,"� Carusone explains.

Armed with his homemade transcripts, Carusone then dispatches a letter or e-mail to corporate executives asking them if they are aware that their ads are running in an hour when Glenn Beck said, "[insert newest offensive sound bite]." Many times, that's enough to make advertisers pull their commercials, although Carusone admits that by now his reputation for peskiness may help grease the wheels. He catalogues his activities on, which includes one running list of sponsors that have dropped the show and another of those that have not.

Critics say Carusone is trying to stifle Beck's constitutionally-guaranteed free speech. Carusone, however, says he's not telling Beck what he can and can't say, only holding advertisers accountable for supporting his program. But his campaign is an effort to target Beck's words using advertising dollars as leverage.

If an email fails to sway a Glenn Beck advertiser, Carusone turns to social networking. He has more than 7,000 followers on Twitter, including such influential ones as Shoq, an anonymous persona with an active following, whom Carusone refers to as "the Batman of Twitter."�

The snowballing impact of thousands of outspoken Twitterers can create major headaches for a company concerned about its image. The Twitter method is so effective that it might be tempting for Carusone to use it all the time, but he says, "My goal is accountability, not public embarrassment. The hope is that by bringing the problem to these companies' attention, it will resolve itself silently."

As a last resort, Carusone picks up the phone. "It's my least flattering method of persuasion,"� he says -- a strange admission, considering that he has eight years of competitive debate experience, including in major national and international tournaments. (Much of that experience came during his four years at Chaminade High School, the same private all-boys Catholic school from which Beck's Fox News colleague Bill O'Reilly graduated.)

The first major victory for the StopBeck campaign came last August, when an executive from Kraft Foods posted the following statement directly on Carusone's site: "We have a longstanding policy not to advertise on programs with extreme or inflammatory content on any network. In recent years, there has been a proliferation of shows with extreme content, including on the political front. These shows often are controversial and do not align with our company or brand values. We do not want to become associated with controversy simply because of the placement of a 30-second spot."� Dumbfounded, Carusone confirmed the statement's authenticity with Kraft before spreading the news.

But it hasn't always been so easy; some of Beck's sponsors have remained impervious to Carusone's prodding. 1-800-PetMeds offered a boilerplate rejection letter. ServPro, a company that repairs fire and water damage, stated that it offers an important service that must reach the widest possible audience. And some of his victories have been short-lived: Nutrisystem recently reversed its decision to withdraw its advertising from Beck, and the company has even gone so far as to block Carusone on Twitter so that he can no longer pester its representatives with direct messages.

All in all, however, Carusone's effort has been a resounding success: So far approximately 320 companies have agreed not to support Glenn Beck with their ad dollars. (Nearly two-thirds of them have chosen to remain anonymous, presumably for fear of retaliation from Beck's legions of passionate fans).

Part of that success can be chalked up to good timing. Carusone launched the campaign just a few weeks before Beck made perhaps his most outrageous comment to date, accusing President Obama of being "a racist‚"� who "has a deep-seated hatred for white people or the white culture." The African-American advocacy group promptly created their own campaign, a partnership that Carusone says "has been vital."� Other advocacy groups have also contributed to the effort periodically, as their particular constituencies have found themselves in Beck's line of fire.

With StopBeck, Carusone tries to occupy the space between media-watchdog organizations (such as Media Matters for America) and issue-based activist groups (such as the Anti-Defamation League). He calls what he does "informed activism" -- that is, action backed by "informed commentary, not just tired slogans that are easy to brush off."�

It's a formula that is well suited to Carusone's cause, according to Ari Rabin-Havt, vice president of research and communication at Media Matters, which has catalogued hundreds of examples of Beck's false and inflammatory statements. Carusone's approach "explicitly shows advertisers what they are supporting with their dollars,"� Rabin-Havt says.

Some opponents of Carusone's efforts argue that he's attempting to stifle Beck's free speech. Carusone, who has focused on First Amendment issues in his law studies, says free-speech rights are something Americans should "cherish and treat responsibly," and he is quick to point out that no one is telling Beck what he can and can't say. Carusone's position is that someone who "willfully and routinely asserts distortions as fact"� should not be given such a prominent platform. That's why he goes after the advertisers -- it's an attempt, he says, "to take away the financial incentive to lie, because the more you reward the lies with increased advertising dollars, the more lies you'll see."

Other critics say that by going after Glenn Beck's advertisers Carusone is barking up the wrong tree. Why not target Fox News president Roger Ailes, or the network's owner, News Corp. chief Rupert Murdoch? Carusone has already tried that, he says -- to no avail, unsurprisingly. Says Mark Crispin Miller, a professor of media ecology at New York University, "Murdoch suffers from Nixon-like pathological stubbornness. The more people criticize him -- even if they are in his own family -- the more he digs in his heels."�

Fox News claims not to be worried about the Glenn Beck advertiser boycott, saying that companies have simply moved their commercials to other shows and time slots. The commercial breaks during Glenn Beck these days are populated by lower-tier advertisers, such as the Jewelry Exchange and Sun Setter Retractable Awnings, and many of the spots run longer than the usual 30 seconds. At one point, to save face, Fox News tried to make it look like business as usual by running free "bonus ads" from sponsors that had previously pulled their spots from Beck's show. Carusone caught on to this practice quickly and brought it to the attention of the advertisers who, in turn, reiterated their positions to Fox News.

Things are even more embarrassing in the U.K., where Glenn Beck is broadcast by News Corp--owned Sky TV. For more than three months, the show hasn't had a single sponsor, so the network runs Sky News briefs in the slots where advertising would normally appear.

From Fox News's perspective, however, “it's probably worth losing the advertisers," says Peter Gardiner, chief media officer at Deutsch Inc. “Beck attracts people to the network, and Fox hopes he will feed viewers to the other shows." Gardiner adds that Murdoch can quite easily "deal with any losses"� from Glenn Beck, since Fox News as a whole is hugely profitable.

As Carusone prepares to graduate from law school, he is still a bit cagey about his future plans. He says he hasn't filed any resumes with law firms (or anywhere else, for that matter), and he won't directly answer questions as to whether he will join a media-watchdog organization or, perhaps, launch his own. “How I can best help remains to be seen," he says, "but I have a few ideas."

One idea that is not on the table is giving up the StopBeck campaign. On the contrary, Carusone is mounting similar campaigns targeting Sarah Palin, Sean Hannity, Rush Limbaugh and CNN. Carusone only started with Glenn Beck, he says, because "he made himself an easy target."� However, he insists that his motivation for launching the StopBeck campaign was not to force Glenn Beck off the air -- he merely wanted to make Beck accountable and sponsors responsible for the programming they support, he says.

With Beck's massive audience and his status as the patron saint of the Tea Party movement, he's not likely to find himself out of a job anytime soon. But the StopBeck campaign has put Fox News in a tricky situation. If the network continues to ignore the advertiser boycott, it will continue to lose revenue and suffer the indignity of having laughably small-time companies sponsor its second-highest-rated show (The O'Reilly Factor is the highest-rated). But if it asks Beck to tone down his rabble-rousing rhetoric, it risks losing credibility with its viewers.

As Carusone says, "Ultimately, Fox hoped I would go away. I won't."�

Allen McDuffee is a New York¬based journalist. He recently launched a blog called Think Tanked.