ST. PETERSBURG, Russia -- Applying a wooden ruler to a piece of A4 paper, Yury Sternik draws a line along its edge. With a pair of scissors, he cuts along the mark and glues the poster to the side of a small cardboard box.

"PUTIN IS TERROR," it reads in block letters. "The police have neutralized every dangerous child and old man roaming the streets with a suspiciously downcast expression."

Beneath the text are two photos from a recent protest in St. Petersburg, during which riot police disperse a crowd demonstrating against the government's plan to raise the retirement age. In one image, a boy is led away by a uniformed officer; in the other, Sternik is seen resisting as he's dragged to a waiting police van.

Minutes after that photo was taken, the 81-year-old was loaded into an ambulance on a stretcher. When fellow protesters tried to free him, Sternik was caught up in the ensuing scuffle and eventually lost consciousness. The story of his treatment quickly spread, and soon became a symbol among the city's activists of authorities' willingness to employ violence in stifling dissent.

A sprightly design engineer with a full head of grey hair and a voice that resonates across the room, Sternik is an inveterate dissident. Born to Jewish parents enticed to the nascent U.S.S.R. from exile in the United States by the promise of socialism, he never endorsed a Soviet regime prone to anti-Semitic policies. In 1958, he began a decades-long stint at a manufacturing plant outside what was then Leningrad. He took leave only to complete his PhD in Moscow and finally retired this spring, after his wife of almost 60 years died.

The Soviet government brooked less dissent than Vladimir Putin's Russia, Sternik says -- "protest didn't even enter most people's minds then." And it's because he believes in Russia's potential for change that he continues to protest. In 2004, he coordinated a citizen's movement that successfully overturned the city's approval of a five-story housing project on the Stalin-era estate he's inhabited since the 1950s. That victory would serve as inspiration for the various demonstrations he's staged since.

The cardboard box, with its scathing slogans, is what he calls his "Sternik hat." Prior to each protest, he designs and prints out four A4 posters, and sticks one to each side of the box. On September 16 he donned it once again to join a sizeable crowd at Sverdlovsk Park, obscuring the bruises he suffered the weekend prior beneath a light autumn jacket.

'Robbed' By Official Corruption

Sternik insists he does not coordinate his actions with supporters of Aleksei Navalny, but says a slice of his monthly pension goes toward the opposition leader's anticorruption campaign. According to Ilya Gantvarg, the deputy coordinator of Navalny's St. Petersburg branch, Sternik enjoys high standing among activists in the city, many of whom weren't even born when Soviet power fell.

"We all respect him greatly," Gantvarg says. "It's amazing that, despite his age, he finds the time and the energy to resist our corrupt regime."

In recent months, Navalny has sought to capitalize on a backlash against the government's controversial pension reform. On September 9, St. Petersburg was among 33 Russian cities that saw protests against the measure. More than 1,000 people were detained that day, according to protest monitor OVD-Info, a figure that belies a disappointing turnout over an issue that has stoked a level of popular anger not seen in Russia for years.

Many Russians see pensions as an income that supplements continued low-wage employment well into old age. But Sternik has no obvious reason to feel robbed. At 30,000 rubles, his pension is more than double the national average, and he exceeds the proposed new retirement age for men by 16 years. However, like many, he's incensed at the level of official corruption, and has seized an opportunity to publicly condemn the elite who profit.

"If there weren't a huge difference in incomes, then maybe it would have been a justifiable measure," he says of the planned pension reform, echoing a sentiment voiced in multiple surveys conducted by the Levada Center, an independent pollster. His children, now in their 40s, try to persuade Sternik to stay home, but ultimately they back his convictions, he says.

​ Eye-Opening Cruise

In 1975, after the Helsinki agreement eased some restrictions on travel for Soviet citizens, Sternik secured permission to visit relatives living in the United States. The local Communist Party cell initially turned down his application, and he spent three months trying to overturn the decision. "Well, since I promised my aunt, I had no choice but to go," he recalls with a big smile over tea in his quaint apartment across the Neva River from St. Petersburg's historic center.

That summer, he boarded a ship bound for New York, a three-week journey with stops in Helsinki, Copenhagen, and other cities few of his compatriots would ever see. It was an eye-opening trip, and it sowed the seeds of a more critical stance toward power back home.

On September 16, Sternik took the subway to Lenin Square, a short walk from the scene of the day's planned protest. En route to the park, the sidewalk was blocked by three riot-police officers, who asked Sternik to cross to the other side of the road. He brought his face within inches of the men's. "Eh?" he asked, a distaste almost visceral flashing across his face. Grudgingly, he complied, and despite the detour, found himself moments later among fellow protesters with his insurrectionary headgear and broad grin.

The day saw no repeat of the violence of September 9. Three people were detained by the police, and one woman hospitalized from injuries inflicted during a standoff with police. Sternik was home by late afternoon, his aim accomplished, and ready to risk arrest or worse when the next chance to protest comes.

He concedes that the Kremlin has triumphed for now, that the day's protests were a mere shadow of the mass unrest over election fraud that engulfed Russia in 2011 and rattled the leadership. But when asked what power a pensioner can have before the arsenal of an authoritarian state, his response is blunt. "People thought communism was eternal too," he says. "It was shocking how quickly it unraveled."