Thuc, a blogger who wrote under the name Tran Dong Chan (Change We Need), was first arrested on charges of "promoting anti-Socialist, anti-government propaganda," according to news reports. On January 20, 2010, he was sentenced by the People's Court of Ho Chi Minh City to 16 years in prison and five years' house arrest for "activities aimed at overthrowing the government" under Article 79 of the penal code.
The court's indictment charged him with disseminating false information through a website and three blogs, according to news reports. He was convicted in part for writing a book called The Vietnam Path, along with two political activists, which the court ruled was part of a plan to create political parties and overthrow the government, according to news reports. Only the Communist Party of Vietnam is allowed to exist in the country.
Thuc maintained his innocence at the one-day trial and claimed he was tortured while in pretrial detention, without giving further details, according to .
His personal blog, Tran Dong Chan, focused on local issues of inequality, social ills, and risks of a possible socioeconomic crisis. He also wrote about sensitive foreign affairs including a March 2009 article called "Obama, China, and Vietnam," which analyzed the countries' divergent approaches to civil liberties, human rights, and economic development.
On May 11, 2012, an appellate court upheld Thuc's sentence in a closed trial, according to news reports. He was initially detained at southern Dong Nai province's Xuan Loc Z30A prison. Thuc was held in solitary confinement from August 2012 to March 2013, and denied access to books, newspapers, and writing materials, according to Radio Free Asia in 2013, which attributed the report to his father.
In August 2012, the U.N. Working Group on Arbitrary Detention adopted an opinion that Thuc's imprisonment was arbitrary and requested that the government remedy the situation in accordance with the Universal Declaration of Human Rights and the International Covenant on Civil and Political Rights. He was transferred to Ba Ria-Vung Tau province's Xuyen Moc prison after a riot among prisoners at Xuan Loc in August 2013.
In 2015, Thuc declined offers of early release made by government officials on the condition that he immediately go into exile in the U.S., according to Defend the Defenders, a human rights organization which cited his father as the source of the information.
In March 2016, Thuc and other prisoners staged a 13-day hunger strike to protest alleged misconduct by prison guards, including the frequent use of solitary confinement and restrictions on receiving written materials from their families, according to Alex Hoang, a family member who wrote about Thuc's situation in mid-year in a CPJ .
In May 2016, Thuc was transferred from Xuan Loc prison camp to a detention facility about 930 miles (1,500 kilometers) away known as Camp No. 6 in central Nghe An province, a move his family members viewed as a retaliatory measure for his protest, Hoang wrote. Prison authorities did not give a reason for his move, which made it more difficult for his family to pay him regular prison visits, according to Hoang.
On May 24, 2016, Thuc staged a 15-day hunger strike to call for a referendum on Vietnam's political system, a fast that made him too weak to stand during a family prison visit on June 1 that year. In August, prison authorities cut the electricity in his cell during extreme summer season temperatures as punishment for his refusal to produce imitation money used during funeral ceremonies as a form of prison labor.
On April 1, 2017, Thuc’s brother Tran Huynh Duy Tan and other family members visited Thuc in prison under the supervision of prison authorities, according to an April 4 post they published on Thuc’s . In the post, Thuc’s family said that he suffers from an eye ailment caused by the lack of light in his prison cell. Prison authorities continued to cut electricity in his dark cell during daylight hours, the Facebook post said.
Authorities refused to deliver him battery-powered flashlights provided by his family on the grounds that electronic devices are banned for prisoners. Authorities also refused to deliver books, magazines, and letters, the Facebook post said.
In May 2018, Thuc announced he would appeal his sentence in light of changes to the national penal code that reduced the maximum penalty for the charge on which he was convicted to five years, according to the , an advocacy group that monitors the status of Vietnamese political prisoners, and .
On September 12, 2018, activists launched a petition seeking a review of Thuc's case based on the amended laws. The online petition, signed by 320 civil groups and individuals, was sent to the National Assembly, the prime minister, state agencies and foreign diplomats, said.
From mid-August to mid-September 2018, Thuc staged a hunger strike for 33 days to protest increased restrictions in prison and to oppose pressure from government authorities to accept an exile-for-freedom deal that he rejected, according to and the 88 Project.
Thuc was still being held at Camp No. 6 in central Nghe An province in late 2018, the 88 Project said.