The Office of the Election Commission (EC) warns that posting text, sharing or commenting on messages that defame political candidates violates the Computer Crime Act.
Facebook, Google and Line accepted a call to remove illegal content within two days by using artificial intelligence to detect fake video clips.
"Any activities that violate the election law taking place offline are also considered illegal when they are put online," Pol Capt Chanin Noilek, chief of the EC's legal department, said at a seminar on the "Scope of Online Election Advertising" held by the IT Press Club.
Candidates and supporters can use the online channel and pay for online advertising freely, but if more than 10,000 baht they need to declare the expense after the election.
Candidates can declare policies as online content for the election campaign, but they must not use any rude words, nor defame, insult or distribute untrue policies or facts.
If any rude or impolite words are found, or any content leads to conflict, those are against the law and the EC can order those who post the content to remove it. They can also inform internet service providers (ISPs), and those ISPs that post such content will face a jail sentence of up to six months, with a 10,000 baht fine as it breaks sections 70 and 159 of the EC law.
In cases where users like, share, post or comment on content that insults others, they will be charged with defamation under the Criminal Act. In cases where content is not true and defames and is distributed online, the content owner will be charged under the Computer Crime Act.
Pol Capt Chanin suggested users only read content that is posted as messages from candidates. Supporters of politicians who distribute illegal content also face a penalty.
In addition, the EC has an electronic war room to monitor online content, detecting and reporting to the commission so it can be removed. The EC has a direct channel to Facebook, Line and Google to remove content within two days, and can go to court within two weeks for an investigation.
The EC is also working with the police to investigate cases, but it requires collaboration with the National Broadcasting and Telecommunications Commission and the Digital Economy and Society Ministry to block websites.
Udomtipok Phaikaset, vice-president of the Thai Webmaster Association, said the ECshould provide a list of all legitimate political party websites to help citizens.