As comfortable Wolf is about the ethics of giving paid speeches to financial firms, for other financial journalists the matter is one of growing angst. These folks worry that their readers and viewers will think they are too close to Wall Street, even if their coverage of the financial industry is hard-nosed and penetrating.

As a result, they weigh each invitation carefully. Take the case of Gretchen Morgenson, an assistant business and financial editor and a financial columnist at The New York Times who won a Pulitzer Prize in 2002 for her “trenchant and incisive” coverage of Wall Street. On occasion she gives paid speeches to universities, as Times policy permits, and sometimes she appears, for free, at financial-industry events—but not without doing due diligence. “I did recently participate in a one-hour question-and-answer session about the state of the economy and markets with about 50 clients of First Long Island Investors, a small, local registered investment advisory firm,” she said in an e-mail. “It does business only in New York and Florida, has 200 or so accounts, and does not conduct securities underwriting or trading for its own account. As such, it would not be a firm I would cover. I received no honorarium for my participation in this session and before I agreed to participate, I checked that the firm had not been subject to any regulatory or disciplinary actions.”

Another prominent financial journalist, who does give paid speeches at Wall Street events, also runs the traps. “I don’t want to be speaking at events run by disreputable organizations—that’s a first filter,” he said.

Are readers really monitoring these journalists that closely? Yes. A financial writer at a leading news organization that bans speeches to for-profit firms told me that, in the current environment, readers are intensely suspicious of how journalists are covering Wall Street. “If I write anything that is even remotely positive about Wall Street organizations, they will send me an e-mail saying, ‘You’re in the pocket of these people,’” this journalist says. “If you were actually in the pocket”—defined, he says, by taking money from the firms for speeches—“that would a real problem.”

Given the varying circumstances and different opinions on the matter, what should the rules be in journalism on speaking fees—taken from Wall Street or anyone else? Robert Dowling, a former assistant managing editor for BusinessWeek who at one point supervised ethics policies, recommends public disclosure—of a journalist’s appearances as well as fees. “It seems hypocritical for the press to criticize Newt Gingrich for taking $1.6 million from Freddie Mac but not tell readers where you as a journalist are earning outside income—and how much,” he says.

I’m certainly no purist on this question. After I wrote a book, published in 2009, about America’s role in the world, I actively sought to give speeches on the university market on this theme, and I still, on occasion, as a freelancer, give paid speeches to nonprofits. I recently was awarded a $1,000 Poynter fellowship to deliver a day’s worth of talks to students at Yale on how media cover Russia and on topics in my book. Such talks can be learning experiences for me—just as Michael Lewis suggested—and there doesn’t appear to be any motive for the university other than to stir thought and debate.

Nor is it evident that Wall Street’s money for speaking engagements has kept journalists, including at outlets with accommodating policies, such as the Financial Times, from providing tough coverage of the financial industry.

Still, the acceptance of speaking fees from Wall Street does strike me as a real problem for journalism. It is a dilemma, most of all, for journalists assigned to the financial industry, because the public has a right to expect that this coverage will not be informed by anything other than the journalist’s reporting and analysis. Any financial journalist—whether a “straight” newsperson or opinion writer—who takes money from Wall Street is inviting skepticism and even cynicism, fairly or not, about the work he or she is doing.

Paul Starobin , a former Moscow bureau chief of Business Week, is the author of After America: Narratives for the Next Global Age.