The thought police would get him just the same. He had committed – would have committed, even if he had never set pen to paper – the essential crime that contained all others in itself. Thoughtcrime, they called it. Thoughtcrime was not a thing that could be concealed forever. You might dodge successfully for a while, even for years, but sooner or later they were bound to get you.

George Orwell

1984. Part 1, Chapter 1. When Winston Smith sets out to challenge the Party’s power, he discovers the real extend of its ability to control and enslave people . In this society thoughts are not free.