Dennis Prager wrote an excellent analysis in October 2007 on anonymity on the Internet, specifically anonymous comments posted in comment sections of blogs, online newspapers, etc. The column can be found here. An excerpt below:
"The Internet practice of giving everyone the ability to express himself anonymously for millions to read has debased public discourse. Cursing, ad hominem attacks and/or the utter absence of logic characterize a large percentage of many websites' 'comments' sections. And because people tend to do what society says it is OK to do, many people, especially younger people, are coming to view such primitive forms of self-expression as acceptable."