New York - Mix blatant bigotry with poor spelling. Add a dash of ALL CAPS. Top it off with a violent threat. And there you have it: A recipe for the worst of online comments.Blame anonymity, blame politicians, blame human nature. But a growing number of websites are reining in online commentary. Companies including Google and The Huffington Post are trying everything from deploying moderators to forcing people to use their real names. Some sites, such as Popular Science, are banning comments altogether.The efforts put sites in a delicate position. User comments add a lively, fresh feel. And, of course, the longer visitors stay to read the posts, and the more they come back, the more a site can charge for advertising.What websites don't want is the kind of nastiness that appeared under a recent CNN.com article about the Affordable Care Act."If it were up to me, you progressive libs destroying this country would be hanging from the gallows for treason. People are awakening though. If I were you, I'd be very afraid," wrote someone using the name "JBlaze."YouTube, which is owned by Google, has long been home to some of the internet's most juvenile and grammatically incorrect comments. The video site caused a stir last month when it began requiring people to log into Google Plus to write a comment. Besides herding users to Google's unified network, the company says the move is designed to raise the level of discourse.A Cheerios cereal commercial featuring an interracial family met with such a barrage of racist responses on YouTube in May that General Mills shut down comments on it altogether."Starting this week, when you're watching a video on YouTube, you'll see comments sorted by people you care about first," wrote YouTube product manager Nundu Janakiram and principal engineer Yonatan Zunger in a blog post announcing the changes.Anonymity has always been a major appeal of online life. Two decades ago, The New Yorker magazine ran a cartoon with a dog sitting in front of a computer, one paw on the keyboard. The caption read: "On the internet, nobody knows you're a dog."At its best, anonymity allows people to speak freely without repercussions. It allows whistle blowers and protesters to express unpopular opinions. At its worst, it allows people to spout off without repercussions. It gives trolls and bullies license to pick arguments, threaten and abuse.But anonymity has been eroding. On the internet, many people may know not only your name, but also your latest musings, the songs you've listened to, your job history and who your friends are."It's not so much that our offline lives are going online, it's that our offline and online lives are more integrated," says Mark Lashley, a professor of communications at La Salle University. Facebook, which requires people to use their real names, played a big part in the seismic shift."As more people go online and we put more of our lives online, we should be held accountable for things we say," Lashley said.Nearly three-quarters of teens and young adults think people are more likely to use discriminatory language online or in text messages than in face-to-face conversations, according to a recent poll from The Associated Press-NORC Centre for Public Affairs Research and MTV.The poll didn't distinguish between anonymous comments and those with real identities attached.'Maturing environment'The Huffington Post is clamping down on vicious comments. In addition to employing 40 human moderators who sift through readers' posts for racism, homophobia, hate speech and the like, the AOL-owned news site is chipping away at anonymous commenting.Previously, anyone could respond to an article posted on the site by creating an account, without tying it to an email address. This year, HuffPo began requiring people to verify their identity by connecting their accounts to an email address."We are reaching a place where the internet is growing up," says Jimmy Soni, managing editor of HuffPo. "These changes represent a maturing [online] environment."The lack of total anonymity, while not a failsafe method, offers people a "gut check moment", Soni says.Newspapers are also turning toward regulated comments. Of the largest 137 US newspapers - those with daily circulation above 50 000 - nearly 49% ban anonymous commenting, according to Arthur Santana, assistant communications professor at the University of Houston.Nearly 42% allow anonymity, while 9% do not have comments at all.In some cases, sites have gone further. Popular Science, the 141-year-old science and technology magazine, stopped allowing comments of any kind on its news articles in September.While highlighting responses to articles about climate change and abortion, Popular Science online editor Suzanne LaBarre announced the change and explained in a blog post that comments can be "bad for science".Because "comments sections tend to be a grotesque reflection of the media culture surrounding them, the cynical work of undermining bedrock scientific doctrine is now being done beneath our own stories," wrote LaBarre.