Cuba's Totalitarian System.
"Over the past forty years, Cuba has developed a highly effective machinery of repression. The denial of basic civil and political rights is written into Cuban law. In the name of legality, armed security forces, aided by state-controlled mass organizations, silence dissent with heavy prison terms, threats of prosecution, harassment, or exile. Cuba uses these tools to restrict severely the exercise of fundamental human rights of expression, association, and assembly. The conditions in Cuba's prisons are inhuman, and political prisoners suffer additional degrading treatment and torture. In recent years, Cuba has added new repressive laws and continued prosecuting nonviolent dissidents while shrugging off international appeals for reform and placating visiting dignitaries with occasional releases of political prisoners."
The above statement of HRW is illustrated in the pages linked above.
From the CDR at the local level over the judicial system, police, ... all are aimed at keeping the regime in power. Cubans face a sophisticated system of repression that controls all aspects of their life. Education, housing, employment, ... even food: all is controlled by the government.
To stand up to the regime means risking all. Not just for your person, but also for your family and friends.
A copy from a Cuban school report listing "good revolutionary behavior".