Defamation laws are not the same in every country. In most countries it is a civil wrong or tort. In some it is a crime. In many countries the burden of proof is on the person claiming that somebody is defaming them. This means they have to prove that the thing that was said about them is false. However, in England, it is the other way around. If somebody claims that a statement is defamation, the person who made the statement has to prove the statement is true.