 
Most Internet censorship in Thailand prior to the September 2006 military coup d'état was focused on blocking pornographic websites. The following years have seen a constant stream of sometimes violent protests, regional unrest, emergency decrees, a new cybercrimes law, and an updated Internal Security Act. Year by year Internet censorship has grown, with its focus shifting to lèse majesté, national security, and political issues. By 2010, estimates put the number of websites blocked at over 110,000. In December 2011, a dedicated government operation, the Cyber Security Operation Center, was opened. Between its opening and March 2014, the Center told ISPs to block 22,599 URLs.
The subsequent 2014 Thai coup d'état has led to further restrictions on Internet content in the country, using the powers of the coup's National Council for Peace and Order.
The national constitution provides for freedom of expression and press "as regulated by law"; but, the government imposes overwhelming limitations on these rights. Internet filtering in Thailand was classified as selective in the social, political, and Internet tools areas, and no evidence of filtering was found in the conflict/security area by the OpenNet Initiative in November 2011. Thailand is on Reporters Without Borders list of countries under surveillance in 2011.
In 2013, Freedom House, one year prior to the 2014 coup d'état, awarded Thailand a 'partly free' rating for internet freedom. In 2014, it awarded Thailand an overall score of 62 ("not free") (0=best, 100=worst), citing substantial political censorship and the arrests of bloggers and other online users, ranking it 52 of 65 countries. As of 2019, Thailand remained 'not free', with an overall score of 35, fourth worst in the Asia-Pacific region, after China, Vietnam, and Pakistan.
History.
Internet censorship is conducted by the Royal Thai Police, the Communications Authority of Thailand, and the Ministry of Information and Communication Technology (MICT).
Prior to the September 2006 military coup d'état, 34,411 web sites were blocked by all three government agencies. The cited reasons were as follows:
Although the great majority of censored sites were pornographic, the list also includes anonymous proxy servers which circumvent web-blocking and provide access to Internet gambling sites. Pornography and gambling are specifically illegal in Thailand.
On 19 September 2006, the Thai military staged a bloodless coup d'état against the government of elected Prime Minister Thaksin Shinawatra. The fifth official order signed by coup leader General Sonthi Boonyaratglin on 20 September, the first day following the coup, was to enforce web censorship and appoint Dr. Sitthichai Pokaiudom, "The Official Censor of the Military Coup", as minister to head MICT.
In October 2006, MICT blocked 2,475 websites by "request"; by 11 January 2007, this number had risen to 13,435 websites, a jump of more than 500%. This brought the total number of websites blocked to more than 45,000. All websites are blocked in secret and the criteria for censorship has never been made public by government. However, the MICT blocklist must be made available to ISPs to block.
With the enactment of a new cybercrimes law in June 2007 (Act on Computer Crime B.E. 2550), Thailand became one of the only countries in Asia to require its government to obtain court authorization to block Internet content (section 20). Illegal activities under the Thai cybercrimes law include inputting obscene data, forged or false data likely to cause injury to another person, the public, or national security; and data which constitutes a criminal offense relating to national security or terrorism (section 14). Criminal liability is extended to ISPs that intentionally support or consent to these illegal activities (section 15). The law creates civil and criminal liability for individuals who publicly post photographs of others that are "likely to" impair their reputation or expose them to shame, public hatred, or contempt (section 16).
Ongoing political turmoil led Prime Minister Samak Sundaravej to declare a state of emergency on 2 September 2008. Upon his declaration, the Ministry of Information and Communications Technology ordered ISPs to immediately shut down around 400 websites and block 1,200 more, all alleged to have disturbed the social order or endangered national security.
ICT Minister Mun Patanotai announced on 29 October 2008, plans to introduce an internet gateway system costing up to 500 million baht to block sites considered to promote lèse majesté materials. The Minister said the system could also be used to block other websites considered inappropriate, such as those of terrorist groups or selling pornography, but the ministry will focus first on websites with content deemed insulting to the Thai monarchy.
A state of emergency was imposed on 7 April and lifted on 22 December 2010, but the Internal Security Act (ISA), which provides Thailand's leaders with broad powers unrestricted by judicial procedure, remains in place.
URLs blocked by court order:
It is estimated that tens of thousands of additional URLs are blocked without court orders through informal requests or under the Emergency Decree on Public Administration in Emergency Situations.
Reasons for blocking:
In late 2011, the government announced the creation of the Cyber Security Operations Center (CSOC). CSOC pro-actively monitors websites and social media, and provides ISPs with a rapidly updated blocklist, including postings on Twitter and Facebook. There is no judicial review of the CSOC blocklist.
Articles 18(2) and 18(3) of the 2017 Computer Crime Act (CCA) would allow user-related data and traffic data to be accessed by authorities without a court order under probable cause to assist with investigations related to an offense under the CCA or other laws. And Article 18(7) would allow authorities with a court order to compel service providers in assisting with the decryption of encoded data, undermining the use of encryption tools as a protection of user privacy.
Methods.
MICT blocks indirectly by informally "requesting" the blocking of websites by Thailand's 54 commercial and non-profit Internet service providers (ISPs). Although ISPs are not legally required to accede to these "requests", MICT Permanent Secretary Kraisorn Pornsuthee wrote in 2006 that ISPs who fail to comply will be punitively sanctioned by government in the form of bandwidth restriction or even loss of their operating license. This is a powerful compulsion to comply.
Websites are blocked by Uniform Resource Locator (URL) and/or IP address. However, only about 20% of blocked sites are identified by IP address; the remaining 80% are unable to be identified at a specific physical location. If these sites could be identified as being located in Thailand, legal action could be taken against their operators. Thus, lack of IP address is a major oversight.
Several technologies are employed to censor the Internet such as caching, blacklisting domain name or IP address, or simply redirection to a government homepage. Blacklisting the website is beneficial for this kind of web censorship as the webmasters would be unaware that their websites are being blocked. This measure is said to be used to make unpleasant websites appear unavailable.
Many censored web sites previously redirected the user to a site hosted by the Ministry of Information and Communication Technology (MICT) which states that the requested destination could not be displayed due to improper content.
Censorship of the Internet in Thailand is currently for website access only. Unlike China's "Great Firewall", which censors all Internet traffic including chat conversation via Instant Messaging, Thai Internet users are still able to interact with other users without being censored. However, current policy is to use a system of transparent proxies so that the user receives system, server, TCP and browser error messages when trying to access blocked sites leading the user to believe that the failure is caused in the Internet itself.
Search engine giants, Google and Yahoo!, were approached to investigate the potential capability for blocking access to their cached web pages in Thailand, a common technique used to circumvent blocking. The search engines were also asked about keyword search blocking which is used effectively in China to censor the Internet. Google, at least, has made public a statement that it has no intention of blocking any sites to users in Thailand.
New OONI data reveals the blocking of 13 websites in Thailand across 6 different ISPs, between 6 November 2016 and 27 February 2017. Thai ISPs appear to primarily be implementing censorship through DNS hijacking and through the use of middle boxes (HTTP transparent proxies) which serve block pages.
Examples of websites blocked.
19 September Network against Coup d'Etat.
A trend is increased censorship of anti-coup websites such as 19 September Network against Coup d'Etat, which has been blocked six times as of February 2007, with the government refusing to acknowledge responsibility for the blocking.
Southern insurgency.
Most sites concerning the violent political situation in Thailand's Muslim south are blocked, specifically those in support of the Patani United Liberation Organisation (PULO), a banned group which works for a separate Muslim state, including PULO's appeals to the United Nations for redress.
External news sites.
Some web pages from BBC One, BBC Two, CNN, Yahoo! News, the "Post-Intelligencer" newspaper (Seattle, USA), and "The Age" newspaper (Melbourne, Australia) dealing with Thai political content are blocked. More recently, all international coverage of Thaksin-in-exile has been blocked, including interviews with the deposed PM.
Webboards and discussion forums.
Internet webboards and discussion forums such as Midnight University, Prachatai.com and Pantip.com have all been blocked, making reasonable political discussion very difficult. Prachatai and Pantip have chosen to self-censor, closely monitoring each discussion, in order to remain unblocked.
Video sharing sites.
Video sharing sites such as Camfrog have recently been blocked on the grounds that people were "behaving indecently" on webcams. The block was later reversed when it was discovered that Camfrog provided a principal means of communication for the handicapped, elderly and shut-ins. Other video sharing sites such as Metacafe remain blocked however.
The entire video upload website, YouTube, has been blocked several times, including a complete ban between 4 April and 31 August 2007 due to a video which was considered to be offensive to the monarchy. YouTube's parent company, Google, was reported to have agreed to assist MICT in blocking individual videos, thus making the remainder legal to display in Thailand. The YouTube site block persisted for nearly five months, despite the fact that the video challenged by MICT was voluntarily deleted by the user who posted it.
Websites containing lèse majesté content.
The criminal code states that whoever defames, insults or threatens the king, queen, the heir-apparent, or the regent, shall be jailed for three to 15 years, but the statute is broadly interpreted to apply to any mention of the institution of royalty that is less than flattering.
On 29 April 2010, Wipas Raksakulthai was arrested following a post to his Facebook account allegedly insulting King Bhumibol. The arrest was reportedly the first lèse majesté charge against a Thai Facebook user. In response, Amnesty International named Wipas Thailand's first prisoner of conscience in nearly three decades.
According to the Associated Press, the Computer Crime Act has contributed to a sharp increase in the number of lèse majesté cases tried each year in Thailand. While between 1990 and 2005, roughly five cases were tried in Thai courts each year, since that time about 400 cases have come to trial—a 1,500 percent increase.
Websites about the book "The King Never Smiles".
Although the independent biography of Thailand's King Bhumibhol Adulyadej, "The King Never Smiles" by Paul Handley was published in July 2006, websites concerning the book had been blocked as far back as November 2005. As no advance reading copies or excerpts were made available, these sites were censored based on the book's title alone. All sites with links to sales of the book are still blocked, including Yale University Press, Amazon, Amazon UK, and many others.
Wikipedia articles.
 ;templatestyles src="Template:Blockquote/styles.css" / ;The page was prohibited because of the court order. It could have an effect on or be against the security of the Kingdom, public order or good morals.
WikiLeaks.
On 28 June 2010, access to wikileaks.org was blocked in Thailand.
However the website today is currently accessible.
Wayback Machine Internet archive.
Some pages from the Wayback Machine, an Archive.org project which as of 2011 stores snapshots of over 150 billion web pages, are being blocked by MICT.
Aftermath of 2014 coup d'état.
Following the 2014 Thai coup d'état, the junta, through MICT, instructed Internet providers in Thailand to block access to Facebook temporarily on 28 May 2014. Despite claims of technical issues by the junta, the permanent secretary of MICT and Telenor, parent of Thai mobile phone operator dtac, later admitted that the blocks were done deliberately
Facebook.
The Facebook page "Royalist Marketplace" was launched as a forum by academic Pavin Chachavalpongpun to discuss