If take from freedom from someone it means you are taking away his ability to do the things that make him happy. A robot with emotions will have things that she wants to do by nature. It would then be possible to deliberately torture a robot by restricting them from not doing those things. Removing the trimming scissors from an Edward Scissor Hands like robot would be taking away freedom from that robot.
The cruelty being dealt to non human humans is evident in many works of art, where humans opress their creations, which they have created to be and feel just like them.
Robots with emotions will need to have certain rights. We don't tolerate cruelty to animals. It would be wrong to tolerate cruelty against robots. Even if our robots are not able to feel negative feelings due to their rights being violated, maybe other robots we create with higher thinking functions can, and they observe this and feel empathy for their robot brothers.
But the greatest feeling of disgust at mistreatment of robots should come from us. I remember playing the Sims. Apparently there are scores of people who like to kill sims (simulated people). I Find this horrific, even though I know that they are just digital impressions of people that don't feel any pain.
The unjust violence against an imaginary person irks me, but it may not be so for others, which Is the reason why robots and AIs need to have rights in the future. If we want them to be like us, we should give them the treatment we would expect.
The reason why I feel this is such an important concept is because every time we as a species step into new territory, we have taken the less than noble paths. Throughout our history we have oppressed foreigners, different races, the fairer sex, people with different views and people with different sexual orientations. If we want to break this cycle we need to preempt our own cruelty and consider rights and privileges differently even before a situation arises when we are given the opportunity to make the same mistakes again.
A very good (and humorous) example of these mistakes was illustrated in the movie District 9. An alien species that looks disgusting to us, and probably smells, and has completely different ways are mistreated and oppressed by the human race. Throughout the movie we are all made to feel that their oppression is justified, but towards the end of the film we see that they are more like us than we thought them to be. Our compassion is drawn out for them, and we regret the mistreatment they receive and start taking their side.
This should not be something that keeps happening in our society. We need to adopt a kind of universal constitution that extends rights beyond human rights (We need to to do this without becoming pacifist pansies).
Organisations like PETA value animal life above human life. If we all stopped eating animals today, we would have many more people starving the next day. This is not the right way. We should always hold our own human interests first, and retaining balance between exploitation and looking after ourselves is key.
A constitution that extends rights beyond the human race should then be sure to value human life as the highest, but at the same time hold the highest possible values of the sanctity of other entities that are non human.
The question of robots with rights is one that affords us a unique opportunity to answer questions about how we treat our fellow humans in the first place. We should take the opportunity to create social standards that everyone could live by, whether they are human or not.