The harshest treatment has been reserved for educated urban bloggers who have taken up the cause of vulnerable rural communities.
On Friday, the blogger, Co Cong Duong, was taken from his prison cell and given an additional five year sentence in addition to the four year term he received last month.
He was accused of “abusing democratic freedoms” for writing in support of farmers who complained of inadequate compensation after their land was seized for industrial development.
The Vietnamese leadership sees a nexus between intellectuals and aggrieved local communities as the biggest threat to its monopoly on power and appears determined to stamp out any sign of such cooperation.
It was particularly alarmed by the scale of protest that followed the Formosa chemical leak off the central coast in April 2016. Demonstrations were broken up and courts imposed sentences of up to fifteen years on bloggers thought to be fanning dissent.
Likewise, the Communist party is hugely sensitive to signs of cooperation between tens of thousands of aggrieved farmers and urban middle class activities.
Do Cong Duong described himself as a citizen journalist and used Facebook to convey his articles about land rights abuses.
He told the court that he was fighting against corruption and injustice, but had done nothing to undermine the party or the state. He received five years after a cursory one day hearing.
His earlier four year sentence was imposed for filming forced evictions and posting them on the internet.
The government is moving to crack down on such uses of the internet with its new “cyber security” law to come into effect in January.
The growing power of the General-Secretary of the Communist party, Nguyen Phu Trong, bodes ill for any activist campaigning for more democratic freedoms in Vietnam.
Trong is set to assume the post of president, in addition to his current responsibilities, in the coming weeks.
He has overseen the enhanced campaign against dissent since winning an internal power struggle in January 2016 and has worked to shore up a one party state that sees all criticism as subversion.