Decades ago on a characteristically arctic day here, a boy named Scott Rosenberg waited with his neighborhood pals as a certain Chevy Impala glided into view. It contained the city's archbishop, and the boys, all of them Roman Catholic except for Scott, pelted the car with snowballs.
The archbishop braked and emerged to chastise his assailants. To Scott, whom he correctly identified as Jewish, the prelate said simply, "You call your rabbi."
Consider this a parable or a metaphor or just a piquant coincidence. Consider it revealing that Shmarya Rosenberg, as Scott is now known, recalled the incident in a recent interview as one of his most enduring memories. Because, lo, these years later, Mr. Rosenberg has made his name and earned equal measures of admiration and opprobrium for lobbing the digital version of snowballs at a great many rabbis.
Blogging on the site FailedMessiah.com, Mr. Rosenberg, 51, has transmuted a combination of muckraking reporting and personal grudge into a must-read digest of the actual and alleged misdeeds of the ultra-Orthodox world. He has broken news about sexual misconduct, smear campaigns and dubious business practices conducted by or on behalf of stringently religious Jews.
Operating thousands of miles from the centers of ultra-Orthodox Judaism in Brooklyn and Jerusalem, waking at 3:30 a.m. and working a dozen hours at a stretch in an apartment cluttered with books, Mr. Rosenberg has had his scoops cited by The Wall Street Journal, Columbia Journalism Review, PR Week and Gawker. The national Jewish newspaper The Forward listed him among the 50 most influential American Jews, and the hip, cheeky magazine Heeb put him in its top 100.
And somewhat regularly, Mr. Rosenberg's in-box brims with missives like this recent one: "what happened to you when you were young that you are so anti haredi' were you abused or molested, you are as false and krum as they come, you are not helping anybody with your negative bent. You wanna bring out sad occurrences in the community, im not sure that its your business to do that, there is such a thing called tznius. And to belittle gedolim whole sale just proves that you are insane."
If you need a Hebrew and Yiddish glossary to fully fathom the diss - "krum" means "crooked," "haredi" means "fervently Orthodox," "tznius" is "modesty" and the "gedolim" are the great rabbis - then you have some sense of the almost claustrophobically inward community that Mr. Rosenberg chronicles.
It is also, not coincidentally to his fervor, the one he used to inhabit. The son of Conservative Jewish parents who ran a beauty supply company, Mr. Rosenberg grew attracted in his late teens to the Chabad movement of the Lubavitch Hasidim for what he described as "the perfect combination of social service and religious mystery."
Mr. Rosenberg found his compelling cause in the plight of Ethiopian Jews seeking to be allowed to immigrate to Israel. His failure to enlist Chabad's support for those efforts in the mid-1980s began a sustained process of estrangement. Still, he continued to worship with a Chabad congregation, study under Chabad rabbis and work in the kosher-meat industry in the Twin Cities.
Only in 2004 did Mr. Rosenberg take the decisive step of learning how to set up a blog. He titled it FailedMessiah - a swipe at what he saw as the hypocrisy of the Lubavitcher rebbe, Menachem Mendel Schneerson, who had died in 1994, and what he perceived as a messianic strain within the Hasidic sect. The first item Mr. Rosenberg posted was a 1984 letter from the rebbe saying there were more pressing needs in the Jewish community than the Ethiopians.
Thus provoked, the Lubavitchers excommunicated Mr. Rosenberg. (The group denies that it has such a formal procedure.)
"I thought I didn't have any future," Mr. Rosenberg recalled. "I was in shock for a long time. I didn't have any friends now. I had no business. I had no synagogue. I was going to be a rabbi. Now that was all gone, too."
Yet, journalistically speaking, Mr. Rosenberg was also liberated. And his indignation with Chabad coincided with a big story later in 2004, when People for the Ethical Treatment of Animals released video of the slaughtering practices inside Agriprocessors, a vast kosher-meat plant in Iowa owned and operated by a Lubavitcher family, the Rubashkins.
Mr. Rosenberg posted a link to the video and went on both to report his own investigative pieces and to spread those of other journalists, particularly Nathaniel Popper of The Forward. When a public-relations company, 5WPR, fabricated online postings by a rabbi who was pushing for ethical reform in kosher foods, it was Mr. Rosenberg who uncovered the "sock puppet" scam.
A recent post, replete with supporting photographs and documents, showed how even after Agriprocessors had been disgraced and its chief executive convicted of financial crimes, members of the Rubashkin family continued to sell meat through a Web site.
In his righteous wrath, though, Mr. Rosenberg has also overstepped. He disparaged the journalistic integrity of Sue Fishkoff, the author of an acclaimed book about the Chabad movement, by referring to her as a "kadesha" - a term from Genesis that means a temple prostitute. After she objected, he posted an apology.
Chabad leaders declined to speak on the record about Mr. Rosenberg, but in general, they say that he has exaggerated the degree of messianism in the movement and that he is driven to settle scores. But they acknowledge that he has gotten some embarrassing things right.
"Shmarya often reminds me of journalism in the old days - when editors would sometimes go at one another physically in the street," Jonathan D. Sarna, a historian of American Jewry at Brandeis University with expertise in Jewish journalism, wrote in an e-mail message. "I know that he is fiercely hated in some Orthodox circles, but he has had many a scoop, and is certainly THE destination for those who want dirt about Orthodoxy exposed to the world."