Last month, I boarded a train with my wife, Tsering Woeser, a Tibetan poet and activist, to travel from Beijing to Lhasa, Tibet, where her mother lives. Plainclothes police were waiting for us at the platform in Lhasa. They ushered us to a nearby police station, where they spent an hour going through our belongings. They were thrilled to find in my backpack a “probe hound,” as we call it in Chinese — a little electronic device that can detect wireless eavesdropping. They asked me why I, a writer, was carrying it. I told them I needed to know whether my home in Lhasa was being monitored.

They confiscated the device.

At the time, U.S. Ambassador Gary Locke was visiting Lhasa. My wife and I had not planned our trip to coincide with Locke’s, but domestic security officials, taking no chances, held us under house arrest. Woeser is a soft-spoken person with a gentle nature, but she does have a record of speaking truth to power on the topic of Tibet. In March, she was honored with the U.S. secretary of state’s International Women of Courage Award.

Chinese authorities, it seemed, wanted to ensure that Locke heard no voice that might spoil the perfect image of Tibet they had arranged for his controlled itinerary. And that meant they needed to keep Woeser at a distance.

We were released after Locke departed, but plainclothes police followed us. One of our friends, noticing them, tried to take a photo, and they, noticing him, smashed his camera. Anyone who dared to speak with us got a threatening “visit” from domestic security. And I was “invited” to the police station for more interrogation about that probe hound.

So I told them the full story.

In the 1960s, Woeser’s father, now deceased, had taken a large number of photos in Lhasa. Woeser thought it would be an interesting project — artistically, if nothing else — to revisit the same spots and take photos, half a century later, from the same angles. To make the project as nearly perfect as possible, she found her father’s camera and bought film for it. Within a few days, she had taken 19 rolls of photos.

When a young friend who was headed back to coastal China came to say goodbye, Woeser asked her to carry the film and get it developed. The friend agreed. The next day at airport security, agents “discovered” in her luggage a knife she had never seen before. The “discovery” triggered an “enhanced examination” of her belongings, which the police took away and then returned to her just as she was boarding the plane.

She checked on the film. The boxes were the same but not the contents. Woeser had given her 19 rolls of exposed Fuji 120 film; the boxes now contained 15 rolls of unexposed Kodak 135 film.

That led Woeser to suspect that listening devices had been planted in our home. Her request to her friend had been made orally and to her alone. No one else had been involved; no telephone or Internet communications were used. That was why I was carrying the probe hound. We wanted to know whether our home was bugged.

I told all this to the police and then asked them to return the probe hound. They refused. It was “counterespionage equipment,” I was told. Citizens have no right to own such a device.

These things happened as the Edward Snowden revelations were attracting the world’s attention. The Chinese government seemed gratified, even pleased. Look! The United States is no better than China, so let’s all just stop the mutual carping.

But let’s not jump to conclusions. How comparable are the cases? Is it conceivable that the United States would tell a citizen that he has no right to a probe hound? In China, the government can enter any space of any citizen anytime it wants. It is the “counterespionage” of citizens that is prohibited.

Wang Lixiong is an author and political commentator. His novels include “Yellow Peril.” This op-ed was translated from Chinese by Perry Link, who teaches Chinese literature at the University of California at Riverside.