Marta Kubišová, a successful pop singer who then signed a manifesto of and became a spokesperson for Charter 77, a civic initiative that criticized the communist regime for not respecting fundamental human and civil rights. Her song Prayer for Marta became a symbol of protest against the invasion of the Warsaw Pact troops into Czechoslovakia in August 1968. During her career, she won The Golden Nightingale prize for the most popular singer of her country three times. In February 1970, the communist regime banned her from singing in public, recording or appearing in media. She has been harassed by the secret political police, particularly after taking over a prominent role in the Charter 77. She could only return to singing in 1989 after the collapse of the communist regime.