The revised Thai criminal code came into force, strengthening the law on lèse-majesté in Thailand to include insult and treating it as a crime against national security.

In Thailand, lèse-majesté is a crime according to Section 112 of the Thai Criminal Code, which makes it illegal to defame, insult, or threaten the king of Thailand, the queen of Thailand, the heir to the throne of Thailand, or the regent of Thailand. Modern Thai lèse-majesté law has been on the statute books since 1908. Thailand is the only constitutional monarchy to have strengthened its lèse-majesté law since the Second World War. With penalties ranging from three to fifteen years imprisonment for each count, it has been described as the "world's harshest lèse majesté law" and "possibly the strictest criminal-defamation law anywhere". Its enforcement has been described as being "in the interest of the palace".

Insult is the infringement of another human's honor by whatsoever means of expression, in particular an offensive statement or gesture communicated, and is a crime in some countries. In a few countries seen as the same, in most the distinction between insult and defamation is that, from a focusing point of view, the former ascribes a value whereas the latter attributes or imputes a fact.

National security, or national defence, is the security and defence of a sovereign state, including its citizens, economy, and institutions, which is regarded as a duty of government. Originally conceived as protection against military attack, national security is widely understood to include also non-military dimensions, such as the security from terrorism, minimization of crime, economic security, energy security, environmental security, food security, and cyber-security. Similarly, national security risks include, in addition to the actions of other states, action by violent non-state actors, by narcotic cartels, organized crime, by multinational corporations, and also the effects of natural disasters.