Notable political prisoners of psikhuskas include poet Joseph Brodsky, dissidents Leonid Plyushch, Vladimir Bukovsky, Natalya Gorbanevskaya, Alexander Esenin-Volpin, Pyotr Grigorenko, Zhores Medvedev, Viktor Nekipelov, Valeriya Novodvorskaya, Natan Sharansky, Andrei Sinyavsky and Anatoly Koryagin, politician Konstantin Päts, and whistle blower Larisa Arap .