India recently mandated local data storage and is seeking to expand its regulation of US firms, particularly WhatsApp, the Facebook-owned messaging application.
Thailand passed its own cybersecurity bill last month, drawing criticism from businesses and civil liberties activists.
Vietnam, meanwhile, remains one of the fastest-growing markets in the region despite the looming new strictures.
A report last year from Google and Singapore's Temasek Holdings likened the country's Internet economy to a "dragon being unleashed." Online travel planning, media, ride hailing and commerce were valued at US$9 billion ($13b) in Vietnam in 2018 and are expected to reach $33 billion by 2025, according to the report.
Activists worry that tech giants such as Facebook and Google, which gave them an exciting new forum for criticism, will prove willing to comply with the government's escalating demands so they can maintain a presence in this booming market.
Unlike China, which blocks access to entire websites and has created its own internet giants, Vietnam has opted to slowly ratchet up its regulations governing tech companies.
Still, rights groups say, the regulations will add to an already repressive environment in the Southeast Asian country. The government "maintains a monopoly on political power and allows no challenge to its leadership," according to Human Rights Watch.
The new law was passed easily despite intense lobbying efforts by US companies, according to Jeff Paine, managing director of the Asia Internet Coalition (AIC), an industry association that includes Google, Facebook and other US tech firms.
Much of the lobbying centers not on the concerns raised by activists but on a pitch to the Vietnamese government that embracing tech companies would bring economic benefits that strict implementation of the law would undercut. The efforts included a sit-down with Prime Minister Nguyen Xuan Phuc last April, Paine said, as well as suggestions for tweaks to the law.
"It was an inspiring meeting," Paine said. "Unfortunately, it was short-lived, because in June when this law came out there were a number of concerns that industry had. I would say this law is the was probably the biggest challenge for many tech companies in 2018."
Vietnam is effectively gambling that its market of about 95 million people is attractive enough that companies will meet its demands rather than walk away. For now, the companies are awaiting final guidelines detailing how the law will be enforced - a process Paine described as "clear as mud."
Rather than building the "robust legal system" needed to promote economic development through technology, the government is "preoccupied with the problems of fake news and whatever can affect political stability," said Vu Minh Khuong, an associate professor at the Lee Kuan Yew School of Public Policy in Singapore, who advised the government on the law.
The Ministry of Information and Communications did not respond to a request for comment. The government said previously that the law is necessary to "protect national defense and ensure social order."
Bkav, a Vietnamese cybersecurity firm, reported that computer viruses caused $642b worth of damage in the country last year and that 1.6 million computers suffered data loss.
The main targets of the new law, according to technology officials and activists, are Google and Facebook.
"The cybersecurity law is an attempt by the government to control the only space where people can talk freely," said Mai Khoi, a prominent Vietnamese singer and political activist.
A spokeswoman for Facebook declined to comment when asked whether the company would comply with the law.
Even before the law was passed, there was a significant uptick in censorship from Google, according to data from Google's Transparency Report.
Between December 2010 and June 2016, the company received five requests for content removal from the government. In 2017, it received 67. Between January and June 2018, the latest available data, it fielded an additional 49 requests, the highest number over a six-month reporting period to date.
Of the 7,366 pieces of content Google has been asked to remove since 2009, 7,359 of them came in 2017 and the first half of 2018. The percentage of requests for removal honoured since 2017 has never dipped below 79 percent. Nearly all of the requests pertained to content on YouTube.
In one example cited by Google, the government asked the company to remove more than 3,000 YouTube videos that mainly criticized the Communist Party and government officials. Access was restricted to "the majority," according to the company.
"We have clear policies for removal requests from governments around the world," a Google spokesman said. "We rely on governments to notify us of content that they believe is illegal through official processes, and will restrict it as appropriate after a thorough review. These requests are tracked and included in our Transparency Report."
Khoi, who met with then-Google Chairman Eric Schmidt in 2017 when he was visiting Vietnam, voiced disappointment at what she sees as the tech firms' failure to take a harder stand.
"These companies are faced with a simple choice between complying with the law - and violating human rights - or refusing to comply and protecting them," she said. "Unfortunately, it seems they have chosen to comply."
The 2017 uptick in requests for removals set off a scramble in Washington, with Google officials meeting with representatives of the State and Commerce departments, as well as members of the US Trade Representative's office, according to a person familiar with the matter who spoke on the condition of anonymity to comment to the media.
Last month, former US ambassador to Vietnam Ted Osius joined Google as vice president for public policy and government affairs in the Asia-Pacific region.
