In many countries, the line between the right to free expression and an individual's right to protect his or her reputation is a blurry one. In the Internet age, the issue has become even more complex.
The Internet has created new opportunities for individuals to express their own opinions, but in many countries, when speaking critically about another person online, users can risk violating laws against defamatory speech.
A defamatory statement  is a false claim that harms a person's reputation and exposes him or her to public contempt, hatred, or ridicule. To be considered damaging, a statement should be objectively false. In most countries, expressing a negative opinion of another person is not seen as defamatory, though there are exceptions. In order for a defendant to be convicted of defamation, prosecutors must also demonstrate how the allegedly defamatory statement hurt the reputation of the plaintiff. For example, if a person were fired from his job due to false claims about him published by a news website, he could pursue a defamation suit against the website or the author of the article.
A recent case  involving the business review site Yelp provides a good example of how defamation can work in the online world. A woman in the US posted a harsh review of a home repair contractor on Yelp, where she accused the contractor of damaging her home, charging her extra money, and stealing some jewelry. The contractor filed a defamation suit against the woman, arguing that the accusations were false and claiming that his company had lost customers because of the damage the post had done to its reputation. According to the Washington Post , the number of defamation lawsuits over online reviews on sites like Yelp and TripAdvisor has grown in recent years.
From country to country, another important distinction to be made is that of whether defamation is a civil or criminal offense. In countries where defamation is defined as a criminal offense, a person who posts an online message criticizing another can face criminal trial and imprisonment. In a civil defamation regime, the poster would simply be sued for compensation by the affected entity. International free expression advocacy group Article 19  describes criminal defamation laws as “inherently harsh” and argues that they have a “disproportionate chilling effect on free expression.” However, civil defamation can also have a chilling effect on freedom of expression by setting disproportionate compensation amounts.
Article 19 has built a useful visualization tool to show the current state of defamation laws worldwide . These interactive maps differentiate between criminal and civil defamation and also feature the countries in which a process of full or partial decriminalization of defamation has been initiated. Article 19 writes  that the goal of the project is to be able to draw a line between defamation laws that serve the legitimate purpose of protecting an individual from unwarranted attacks based on false information and laws are drawn explicitly to curtail freedom of expression. Visit their site  and mapping project  to learn more.