RIYADH, Saudi Arabia тАФ One day in November 2015, Saad Almadi typed out a 14-word post on Twitter about Saudi ArabiaтАЩs deputy crown prince.
тАЬMohammed bin Salman has taken over the economy, defense and everything under the king,тАЭ he wrote, replying to a professor who is a fierce critic of the kingdomтАЩs monarchy.
A Saudi-American dual citizen living in Florida, Mr. Almadi had little reason to believe his post would attract attention. He was a retired project manager, not an activist, and his words were largely factual тАФ Prince Mohammed had taken control of many of the levers of power since his father became king that year. By 2017, he would push aside a cousin to become heir to the throne.
Yet the tweet resurfaced as evidence seven years later when Mr. Almadi, 72, was arrested during a visit to Saudi Arabia. Along with other Twitter posts he wrote that were critical of the Saudi government тАФ and an тАЬinsulting pictureтАЭ of Prince Mohammed saved on his phone тАФ the tweet was cited as proof that he had тАЬadopted a terrorist agenda by defaming symbols of the stateтАЭ and тАЬsupported terrorist ideology,тАЭ according to court documents.
His prosecutor requested a severe punishment, тАЬto rebuke him and deter others.тАЭ In October, Mr. Almadi was sentenced to 16 years in prison, lengthened on Feb. 8 to 19 years after he appealed.
тАЬMy father is nowhere near being a dissident,тАЭ said his son, Ibrahim Almadi, describing him as an open-minded man who spent his retirement traveling, hiking and wine tasting. Now he is being held in Al-HaтАЩir prison, a facility in the Saudi capital, Riyadh, that houses members of Al Qaeda alongside political activists.
Saudi Arabia has always been an authoritarian monarchy with limited freedom of speech. But 10 years ago, Mr. AlmadiтАЩs Twitter account, which has fewer than 2,000 followers, might have prompted a warning or an interrogation. Under Prince Mohammed, now prime minister, harsher punishments are being meted out to citizens who criticize their government, while the defendants on trial have become increasingly less prominent.
тАЬThe scope of oppression really is unprecedented,тАЭ said Hala Aldosari, a womenтАЩs rights activist who left Saudi Arabia in 2014 for a postdoctoral fellowship in the United States and said she never felt safe enough to return.
Since then, Prince Mohammed has rendered the conservative Islamic kingdom nearly unrecognizable, setting in motion seismic changes тАФ some of which activists like Ms. Aldosari spent years campaigning for.
He launched an ambitious plan to diversify the oil-dependent economy and ended a slew of religious and social restrictions that many Saudis found suffocating. Women, barred from driving until 2018, now work as Amazon delivery drivers, chief executives and ambassadors. Music, once effectively prohibited in public, thumps inside dimly lit restaurants where young couples flirt. The gender segregation that shaped public life for decades has dissolved.
At the same time, the modest space for political discourse has shriveled.
тАЬItтАЩs a bittersweet moment in history, where you see the fruits of your mobilization somehow yielded, but for the wrong reason,тАЭ Ms. Aldosari said. тАЬThe people are being shut down or silenced in return for giving them certain rights.тАЭ
Since 2017, the Saudi authorities have arrested hundreds of public figures across the political spectrum, including Snapchat influencers, religious clerics, billionaires and several of the princeтАЩs own cousins. The killing in 2018 of the Washington Post columnist Jamal Khashoggi by Saudi agents in Istanbul, prompting international outrage, was the most dramatic example of a broader crackdown that has continued to deepen since his death.
The authorities have paid special attention to Twitter, which is widely used in the kingdom.
Noura al-Qahtani, who ran an anonymous Twitter account, was among several people put on trial last year in relation to social media activity. On her account, where she had roughly 600 followers, she called for anti-government protests, criticized some social liberalization measures and wrote that Prince Mohammed was тАЬnot good enough to be a prince.тАЭ
After a court found her guilty of тАЬchallenging the faith and justice of the king and the crown princeтАЭ and тАЬsupporting the ideology of people who strive to disturb public order,тАЭ among other charges, she was sentenced to 13 years in prison. On appeal, she pleaded for mercy, saying that she was nearly 50 and had five children to take care of, according to a copy of her verdict. Instead, the panel of judges lengthened her sentence to 45 years in prison.
Around the same time, Salma al-Shehab, a Saudi doctoral student at Leeds University in Britain, was sentenced to 34 years in prison, largely in relation to following Saudi dissidents on Twitter and sharing their posts, according to a copy of her verdict.
The court sentenced both women under counterterrorism and cybercrime laws. Both were given an additional penalty at the discretion of the judges.
A Saudi official said in a statement to The New York Times that the government was studying and putting new measures in place to enhance human rights, including changes to the judicial system. However, Saudi Arabia тАЬmaintains a zero-tolerance policy when it comes to terrorism,тАЭ the official said, speaking on the condition of anonymity in line with government protocol.
The official did not respond to questions about specific prisoners, including Mr. Almadi, Ms. al-Qahtani and Ms. al-Shehab, saying only that тАЬcases of individuals that violate national laws are clearly differentiated from peaceful expressions of opinion.тАЭ
What we consider before using anonymous sources.┬аDo the sources know the information? WhatтАЩs their motivation for telling us? Have they proved reliable in the past? Can we corroborate the information? Even with these questions satisfied, The Times uses anonymous sources as a last resort. The reporter and at least one editor know the identity of the source.
Yet a review of the detaineesтАЩ Twitter accounts тАФ which were the basis for their indictments тАФ did not reveal posts professing support for militant groups or endorsing violent action, aside from a vague tweet by Ms. al-Qahtani that referred to тАЬremoving this tyrant from the face of the earth,тАЭ without mentioning a name. Instead, their prosecutors cited posts critical of the government or royal family members and labeled them terrorism-related views that threatened state security, according to court documents.
Until recently, prison sentences longer than 20 years were rare in the kingdom, and Saudis with American citizenship or ties to local elites, like Mr. Almadi, would have been able to draw on connections to protect themselves.
тАЬOne of the merits of Mohammed bin Salman is that heтАЩs created equality of injustice for all,тАЭ said Taha al-Hajji, a Saudi lawyer who lives in exile in Germany.
The тАЬred linesтАЭ that curbed freedom of expression were also more obvious under previous rulers: the royal family, the king, Islam. Now, many people have тАЬabsolutely no ideaтАЭ what is permissible, said Hussein Ibish, a senior resident scholar at the Arab Gulf States Institute in Washington.
тАЬItтАЩs designed to create a climate of intimidation, at the political register, which is meant to inoculate the regime,тАЭ he said.
In an interview in 2018, Prince Mohammed denied creating an atmosphere of fear. If he had, he added, it was тАЬa small priceтАЭ to pay to тАЬget rid of extremism and terrorism without civil war, without stopping the country from growing, with continuous progress in all elements.тАЭ
Many Saudis are deeply disturbed by the crackdown, even if it has not touched them personally. And yet the rapid transformation of their country offers plenty of rewards and distractions that have also been widely welcomed. High oil prices last year helped the economy grow by more than 8 percent, the fastest rate among the Group of 20 industrialized nations.
тАЬThe kingdom is in a sensitive historical transformation phase in all aspects,тАЭ said Salman Al-Ansari, a Saudi political analyst. тАЬNo one can deny the speed in which the reforms are taking place. But like anything else, reforms come with a cost.тАЭ
Some Saudis believe the trade-off is worth it. To others, including Ms. Aldosari, it is a betrayal.
тАЬThis is not what we aspired to,тАЭ she said. тАЬWe aspired for a community where we are heard, where we are seen, we are respected and we are included in decision-making.тАЭ
Ms. Aldosari blamed American and European foreign policies for the escalation in repression, saying that foreign governments had elevated other goals тАФ like getting Arab governments to normalize relations with Israel, or securing stable oil markets тАФ at the expense of human rights.
The Biden administration pledged to put human rights тАЬat the centerтАЭ of American foreign policy. When President Biden visited Saudi Arabia last summer and shared a fist-bump with Prince Mohammed, Saudi dissidents saw it as a retreat.
тАЬAdvancing human rights in Saudi Arabia is a key priority for the United States,тАЭ the State Department said in a statement, noting that U.S. officials тАЬregularly raiseтАЭ cases, including those of Mr. Almadi, Ms. al-Shehab and Ms. al-Qahtani, with Saudi officials. тАЬWe continue to have significant concerns with the imposition of severe sentences for the exercise of freedom of expression.тАЭ
There are also a growing number of Saudis living in exile in the United States, unable to reunite with their families. Among them is Maha al-Qahtani, whose husband, Mohammed al-Qahtani, was once a prominent Saudi political activist. (They are not related to Noura al-Qahtani.)
An economics professor, Mr. al-Qahtani co-founded an independent human rights organization in 2009. In 2013, he was sentenced to 10 years in prison.
Maha al-Qahtani eventually settled in the United States with their five children, counting the years until her husbandтАЩs sentence ended in November.
In October, they were preparing for his release, gathering the gifts they bought while he was in prison, when Mr. al-Qahtani stopped calling home. Maha al-Qahtani sought help from every authority she could reach out to, but found no explanation. Mr. al-Qahtani has effectively disappeared.
тАЬThis is the father of my children, my husband, my love,тАЭ she said in a phone interview, her voice breaking. тАЬWhere are you?тАЭ
Karen Zraick contributed reporting from New York.