If the internet is, as it's often called, the Wild West, then the comments sections of popular blogs are its Deadwood: a lawless no-man's-land of profanity, brawling and every variety of ignorance and crassness.

Two recent events have made this situation clearer than ever—and, in the process, raised questions about whether the people who own and write blogs can or should be held responsible for the excesses of their readers.

On the Huffington Post, discussion took a nasty turn last month after it was reported that Nancy Reagan had been hospitalized after a fall. Although the site's policy specifically prohibits comments that "celebrate the death or illness of any person," some commenters did exactly that, thus attracting the wrath of Fox News host Bill O'Reilly, who compared Arianna Huffington to a Nazi for her role in enabling such vileness.

(The irony of resorting to overheated, spiteful invective in order to decry the use of overheated, spiteful invective apparently escaped O'Reilly.)

Meanwhile, in Chicago, 40-year-old advertising executive Paul Tilley jumped to his death from a hotel room. Press accounts linked his suicide, albeit tenuously, to critical posts and anonymous comments about him on ad-industry blogs. (Tilley's friends dismissed any such connection.)

Advertising Age columnist Bob Garfield, like O'Reilly, brought in the Nazi comparison, seeing an echo of Hannah Arendt's phrase, "banality of evil," in the cruelty of blog pile-ons.

"What passes online for opinion, analysis, criticism, and commentary too often lacks logic, coherent argument, evidence, intellectual rigor, or even simple honesty," Garfield wrote. "It wallows instead in snide cheap shots and ad hominem bile, scurrilousness and schadenfreude, free-floating hostility, and bullying disguised as wit."

You don't need to believe that blogs killed Paul Tilley to agree that there is such a thing as "too far," and that many anonymous Web comments go there. But what's to stop them?

Not the law—at least not for now. Section 230 of the Communications Decency Act, passed in 1996, ensures that website operators and internet-service providers can't be prosecuted for libelous or otherwise unlawful statements generated by third parties (although the third parties themselves can still be held liable, provided they can be identified).

In fact, Section 230 was originally written with the intention of cleaning up the Web, according to Thomas Burke, a partner in the San Francisco law firm David Wright Tremaine, who specializes in First Amendment law.

Prior to the passage of Section 230, internet companies feared that by editing or censoring comments, they were acting as publishers of the comments, thus sacrificing what's known as "conduit immunity." Section 230 allowed them to make "good faith" efforts to exercise some control without incurring liability.

"Of course, in practice it didn't work out that way," says Burke. "A lot of sites said, 'Well, we have immunity, so we're not going to do a thing.'" Still, he says, the courts have "with very few exceptions held that Web owners are not responsible and have immunity for content and comments posted by third parties, period."

Yet it's possible to see the legal consensus shifting as the line between first-party and third-party content fades. No one has done more to blur this line than Gawker Media, which regularly highlights the best comments and reader-suggested captions, selected by editors, in space normally reserved for editorial writing; invites readers to contribute their knowledge to developing stories; and hosts discussions between writers and readers in the comments section.

Gawker has also hired exceptional commenters to write for the site, and recently gave commenters the capability to embed video clips in their comments, in effect turning them into mini-blog posts.

It's obvious why Gawker puts so much energy into cultivating its commenters: Because they click on the same item over and over, comment traffic grows at an exponential rate. Gawker Media's traffic doubled between February 2007 and February 2008, but its volume of comments quadrupled, says owner Nick Denton.

These kinds of tactics could put blog operators at risk of forfeiting their Section 230 protection, says Jonathan Kirsch, a publishing and intellectual-property attorney based in Los Angeles.

"There is a threshold you cross as the editor and publisher and operator of a blog where [third-party content] is no longer immunized, because in a sense you've adopted it by selecting it out and featuring it," he says.

"It's the passivity of the blog operator that is the source of the immunity," Kirsch adds. "If you take something and you feature it, you boldface it, you take it out of the general run of postings and highlight it, then you're approaching a line, and you may have crossed the line."

Some questions about just how far Section 230 protection extends may be answered later this month, when the Ninth Circuit Court of Appeals rules on the case of Fair Housing Council of San Fernando Valley v. Roommate.com.

"It's going to be the first time a full federal appellate court has looked at the difference between content that's created by a third party and content that's either invited by or mixed with content created by the site itself," says Burke. "I don't think there's any website today that isn't or shouldn't be closely following what happens with that decision."

But that still leaves the matter of conscience. Jeff Jarvis, a blogger who has written extensively about the ethics and economics of Web publishing, says it's not as simple as saying that egregious comments should be deleted.

"I don't think there is a blanket rule," Jarvis says. "Part of the problem is that there is a falling bar on the definition of offensiveness. We live in an age of offense and political correctness when someone can be offended by anything said and someone can insist that speech should be silenced. There's danger there. In a free democracy and an open market, we must value open discussion and the exchange of views and ideas. So who's to say what goes too far?"

"There's nothing wrong with setting ground rules and making participants stick to them," agrees Andy Schotz, chairman of the Society of Professional Journalists ethics committee. "Some people, though, don't mind a free-for-all atmosphere. Readers can adjust their opinion of the credibility of the site accordingly."

Clearly, the Huffington Post believes it has a responsibility to filter out the worst of the worst. After O'Reilly's criticism, the site has quietly encouraged its moderators to be extra careful not to post comments that violate its guidelines.

"There's a zero-tolerance policy when it comes to abusive comments," says a spokesman. "For the most part, our conversations are completely civil, but we have more than 400,000 comments each month."

Then there's Gawker. Although its comment forums can get as rowdy as Deadwood's Gem Saloon, Gawker seldom, if ever, deletes individual remarks.

Explains Denton, "I look at Gawker comments as a party. We don't take responsibility or credit for individual comments, but we have the right to invite or disinvite guests and throw the best party we can.

"Just as a host isn't responsible for the vomit in the corner," Denton adds, "we don't take responsibility for individual comments."