On Twitter, 6,000 tweets are published per second on average, or 500 million tweets every day. How many of these millions of tweeters, when they retweet, are thinking about defamation law? It may or may not be illegal for you to retweet someone else's defamatory tweet depending on the country. Defamation, to put it simply, occurs when someone publishes a false, unfounded, and reputation-damaging remark about another individual.