Kammala jumla mai zuwa: Plyushch ya zama mai adawa ta hanyar ɗaukar matsayin jama'a game da batutuwan siyasa masu zafi na lokacin. A cikin 1968 ya nuna rashin amincewa da rashin bin doka na Galanskov-Ginzburg ta hanyar aika da wasika zuwa Komsomolskaya Pravda, wanda ba a buga ba. Lokacin da sojojin Soviet
Bayan mamayewar Czechoslovakia a 1968, Plyushch tare da wasu 'yan adawa na Soviet 16 sun sanya hannu kan wata sanarwa ta haɗin kai tare da motsi na dimokiradiyya a Czechoslovakia. A wannan shekarar ya shiga Kungiyar Initiative for the Defense of Human Rights a cikin USSR, wanda ya aika da wasika zuwa ga Hukumar Kare Hakkin Dan Adam ta Majalisar Dinkin Duniya tana neman ta bincika keta hakkin da USSR ta yi na 'yancin yin imani da' yanci da kuma yada su ta hanyar doka. Plyushch na ɗaya daga cikin mutane goma sha biyar da suka sanya hannu kan wata takarda ga Kwamitin Kare Hakkin Dan Adam na Majalisar Dinkin Duniya. Saboda koma baya daga matsayinsa na siyasa, an kore shi daga Cibiyar Cybernetics a 1968, kuma KGB ta kwace wasu rubuce-rubucensa kuma ta yi masa tambayoyi sau da yawa.