No one has a right to take anyone else's life, and the Bolsheviks certainly did just that. They took lives of people who weren't involved in the destruction of the Empire (I don't think that Nikolai himself deserved death, though he was a rather inept ruler). The only "fault" of the Family was that they were born or married into their postions. However, that doesn't mean that death is the way to go. Blood will be answered with blood, and that is exactly what took place in Russia in the years after the revolution.