Twenty-seven-year-old Moscow mathematician Semyon Krasotkin is accused of high treason. Investigators allege that he sent paid reactions worth a total of 2,200 rubles to Ukrainian and Russian opposition Telegram channels. According to Krasotkin’s relatives, FSB officers beat him and tortured him with electric shocks after he was detained. His is not the only such case: human rights defenders are already aware of 11 criminal prosecutions over Telegram Stars. T-invariant tells Semyon Krasotkin’s story and examines how ordinary reactions in a messenger app can become grounds for criminal prosecution.

Sofia Rosenfeld has spent her life studying Arctic birds: traveling on expeditions to the Far North, following flocks of geese in a seaplane, and fighting to protect rare species. Now one of Russia’s leading ornithologists, a Doctor of Sciences in Biology, has been sentenced to three and a half years in a penal colony — for two 1,000-ruble donations to the Anti-Corruption Foundation (FBK). Rosenfeld partially admitted guilt: she explained that she had been unable to cancel the recurring payments because she was on an expedition without communications. T-invariant explains why the scientist refused to leave Russia, how the trial unfolded, and what Russian science stands to lose.

The Supreme Court of the Komi Republic has sentenced philosopher Nikolay Zyuzev to seven years in a strict-regime penal colony on treason charges. Zyuzev, who holds both Russian and Canadian citizenship, is one of the best-known scholars of the legacy of the Russian-American sociologist Pitirim Sorokin. He left Russia after the war began, but in the summer of 2025 he returned to his native village in Komi [a republic in northwestern Russia — T-invariant], where he was arrested. According to the FSB, the scholar was training leaders of national liberation movements among Russia’s small Indigenous peoples and receiving funding for his project from foreign organizations. T-invariant looks at what Zyuzev worked on, why he kept coming back to Russia, and what his friends and colleagues make of the treason charges.

22-year-old mathematician Leonid Katz, a graduate of the “Intellectual” school for gifted children and holder of a bachelor’s degree from the Higher School of Economics, has been arrested on treason charges. For the previous two months he was subjected to so-called carousel arrests. Katz is accused of making donations to a charitable fund that assists Ukrainian children. After his detention, he was tortured — T-invariant learned this from two sources.

The Gatchina District Court has resumed hearings in the case of Dmitry Bogmut, a technician at the Petersburg Nuclear Physics Institute named after B.P. Konstantinov (part of the Kurchatov Institute). After the onset of the war in Ukraine, Bogmut posted anti-war videos in a private thread on a forum with only a dozen users. He has been held in a pre-trial detention center for a year and a half and faces up to ten years in prison. Court hearings are regularly attended by a crowd of men in camouflage, seemingly organized as “extras”, identified as “Donbas volunteers.” Meanwhile, the names of activists supporting Bogmut have been publicly disclosed by state news agencies, leading to threats against them.