It's a cold, overcast afternoon, but Su Yutong is in a cheerful mood as she walks in a Berlin park.

Her hat askew and hair in pigtails, the 47-year-old proves popular among the animals. A French bulldog runs over to greet her. Swans and ducks paddle close.

Swinging her sequined purse as she walks, Su brags to me about how well she plays ping pong. Her manner is a contrast to the Berliners hurrying by on this windy day.

But the journalist's seemingly carefree attitude belies something darker.

Heading back to her apartment, Su says the buildings look different in the daylight. As someone targeted frequently by the Chinese government, the Radio Free Asia reporter prefers to walk at night.

"Because in the evening, no one knows me," she said.

You don't have to hear much of Su's story to understand why she prefers anonymity.

Held under house arrest in China before fleeing to Europe, the journalist is still targeted for her coverage of human rights and politics. From smear campaigns and people sharing her address on an underground sex website, to false bomb threats made in her name, the harassment has left a deep mark.

"I keep telling the truth, so they want me to shut up, including by threatening me," she said, in reference to the Chinese government, which she and others say is behind the attacks.

For more than a decade, Beijing-backed harassment has been the reality for Su. China ranks among the worst perpetrators of what is known as transnational repression, but even by those standards, Su's case is extreme, experts say.

"The everyday implications of transnational repression are vast," said Gözde Böcü, a researcher at the Citizen Lab. The University of Toronto group focuses on digital threats to human rights.

There's the immediate effect, but the daily fallout is more severe. Long-term consequences include paranoia, depression and isolation, which experts say can also give perpetrators what they want most: silence.

Over the past decade, at least 26 governments have targeted journalists abroad, according to Freedom House. The harassment against Su underscores a broader pattern in which authoritarian governments are increasingly comfortable reaching across borders to target their critics.

Neither China's Foreign Ministry nor its embassy in Berlin replied to VOA's multiple emails requesting comment for this story.

It's been more than 10 years since Su last set foot in China, but Beijing is still home. Born and raised in the country's capital, Su decided to pursue a career in journalism because of the lack of free-flowing information there.

"China blocks the truth. It needs to have a lot of journalists to tell the real stories, tell the real events and the truth, so I decided to become a reporter," Su said.

She worked at Radio Beijing but left in 2004 due to government censorship.

In 2010, Su made a fateful decision: She distributed Li Peng Diary, a book by the former premier about Tiananmen Square that's banned in China.

"I had to make it public," she said. "After it was published, I became very dangerous."

Authorities raided Su's home and detained her, but public pressure pushed authorities to place Su under house arrest. During the Dragon Boat Festival in June that year, only one officer was left guarding Su's house. The journalist seized the opportunity to escape.

"I called my mom on a public phone. I didn't say goodbye. I didn't tell her I was leaving," she said. "It was a very painful and sudden decision."

With the help of colleagues and friends, Su fled to Hong Kong and then on to Germany.

More than 7,300 kilometers lie between Berlin and Beijing, and for a while that distance helped Su feel safe. Slowly rebuilding her life, she worked first at the German public broadcaster Deutsche Welle before moving to VOA's sister outlet Radio Free Asia.

"When I arrived in Germany, at least I was able to write freely," she said. "I thought Germany was very safe."

But the distance began to shrink. And that, says Mareike Ohlberg, is often the goal.

Ohlberg researches China at the German Marshall Fund think tank in Berlin. From her office, with a view of the Reichstag, she said, "The basic tactics of transnational repression are usually geared towards showing people that they can't get away from the Chinese government. To show that we can get you anywhere, we can find you anywhere."

What's known in China as the "three afflictions" helps explain why Beijing's harassment is so aggressive, according to Ohlberg. Under Mao Zedong, China no longer had to worry about being bullied by foreign powers. In turn, Deng Xiaoping addressed poverty and hunger. As this narrative goes, Ohlberg said, the last main affliction is criticism of China, and it's President Xi Jinping's responsibility to root it out.

"The Party can shut up criticism inside of China. But is it really a strong country if it can't do the same overseas?" Ohlberg said about Beijing's mindset. "That is a big part of what we're seeing."

In 2011, Su led a solidarity campaign for Ai Weiwei after the artist was secretly detained in China. In response, a Chinese-run news site posted doctored photographs appearing to show Su naked and falsely referring to her as Ai Weiwei's mistress.

From there, the harassment escalated.

Government-run outlets including the Global Times launched campaigns against her. On the social media platform X, then known as Twitter, insults like "prostitute" and "dog" were common. Death and rape threats were frequent, too. Deepfake pornographic images spread on social media.

Su says she was surveilled at protests outside the Chinese Embassy in Berlin, and on multiple occasions, Chinese authorities offered her large sums of money to stop work.

In a more unsettling case, in 2022, men began ringing the doorbell to her apartment, saying they were responding to a sex worker advertisement on an underground website. Su suspects Chinese operatives posted her address to the site.

"I felt very disgusted and very humiliated," Su said, adding, "I was afraid to walk down the street."

The sexualized harassment mirrors broader strategies that repressive governments use to target women abroad, says the Citizen Lab's Böcü. It's "a devastating practice that can silence female journalists," she said.

The fake advertisement isn't the only time Su's identity was stolen and used against her.

In February 2023, unknown people began booking rooms at luxury hotels around the world, from Houston to Istanbul, under the names of Su and two other activists. They then called in fake bomb threats in a process known as swatting. Again, the Chinese government is the prime suspect.

At the time, a spokesperson from China's Washington embassy told VOA they were aware of the specifics of the case but that China "firmly opposes" the U.S. smearing its reputation.

"The accusation of 'transnational repression' is totally made out of thin air. The U.S. attempt to hype up 'China threat' and tarnish China's reputation is doomed to fail," the spokesperson said via email.

Transnational repression is typically either digital or physical. The former is easier and cheaper to perpetrate, according to Ohlberg. By contrast, what Su has faced is more expensive and time-consuming to carry out.

"That tends to be reserved for people that are at the top of the Chinese government's list," Ohlberg said. "Pretty much anything goes — anything that the party-state thinks it can get away with internationally."

Following the harassment directed at Su, Berlin police recommended she change her address.

It's been 10 months since Su moved, and her new apartment is still mostly empty.

White walls meet high ceilings with ornate crown molding.

Su is learning her way around. Coming home after a walk, she accidentally bumps a light switch in the foyer, triggering an unexpected display of disco lights. Erupting into laughter, Su says the previous owner left them.

Over the years, Su has left a trail of apartments in her wake.

There's the old apartment she still owns in Beijing. She wants to sell, she said, but China has resisted giving her a document necessary for the sale. There's also her other Berlin apartment.

Both still have their furniture and decorations: time capsules of periods of a life she can't retrieve.

Being forced to move is one of the obvious effects of the harassment Su has faced. Other ramifications are subtler and deeper felt, like food. "I think everyone has memories of food as a child," she said.

The German capital has a respectable Chinese food scene, but Su can rarely enjoy it.

Dining out increases the risk of running into officials from China's Berlin embassy, she said. Another concern is that some Chinese restaurants around the world have been found to be secret overseas police stations run by Beijing, according to a report by the human rights group Safeguard Defenders.

Unable to enjoy the comforts of a meal in a Chinese restaurant, Su has become a skilled chef. "I slowly learned everything," she said.

Over a conversation reaching into the night, Su whips up several dishes: fried rice, tofu, cucumber salad, fish, dumplings, sesame buns. Wearing a hat — she always wears a hat — she serves jasmine tea and red wine, the latter a gift from a German lawmaker.

The journalist alternates in and out of levity. She boasts that unlike Elon Musk, she can get into the exclusive Berlin club Berghain. (Vice reported in 2022 that bouncers turned the tech billionaire away. Musk tells a different version.) Su smirks at the comparison then switches to more serious matters, like how her suspicion about Chinese restaurants has given way to suspicion about Chinese people in general.

In her free time, Su likes to help fellow dissidents still inside China. But in Germany, she worries whether members of the diaspora are actually reporting back to Beijing.

"I became very, very cautious," she said.

That wariness is common among those targeted by transnational repression, according to Böcü.

"People fear that other actors or individuals within the community could spy on them. And these fears are not unfounded," she said. "Growing mistrust in these different communities is also a big problem."

Su is doing better now, but for a two-year period she hardly left her apartment. And when she did, she said, "I kept checking to see if there were any suspicious people around me."

But, says Su, fear is what she believes drives Chinese authorities. "They are afraid of information, afraid of the truth," she said.

And while the harassment hasn't stopped, Su says the harmful effects are waning. Through everything, Su never stopped reporting because backing down to the Chinese government was never even a consideration for her.

"They didn't expect me to slowly come out of that shadow. I think they should be afraid, not me," she said. "They can't shut me up. They can't achieve this goal."

Reporter: Liam Scott; Editors: Jessica Jerreat, Holly Franko; Camera: Jonathan Spier