One of the most commonly cited characteristics of human rights is their inalienability. Human rights aren’t granted to people by a sovereign, a law or a tradition, and hence can’t be taken away. They can of course be violated, but violating rights doesn’t mean taking them away. If you’re tortured you still have a right not to be tortured. In a sense, you only have rights – or, in other words, your rights are only real – when they are violated. When rights aren’t violated they move to the background, as self-evident facts not even worthy of being mentioned.
The question here is not whether rights can or cannot be taken away, but whether people can give them away. I think people can’t give away their rights – people are human and hence they have certain rights – but what they can do is waive their rights, meaning that they insist that they don’t want others or the state to intervene in order to enforce respect for their rights. If someone wants to sell herself into slavery, submit herself to cruel treatment, sell her organs, let herself be cannibalized or used in a dwarf-throwing competition, then that person should be free to do so, even if it means that her rights are violated. If those rights violations are her free, conscious and informed choice, we’ll have to respect that choice. She still has her rights but chooses to allow violations of her rights.
Rights are important because they are important to people. They aren’t important as such. If certain people no longer deem them important, then they are no longer important for them. We can’t force people to have their rights respected. That would be a lack of respect for people’s moral autonomy, their dignity and freedom, even if their choices imply giving up their dignity and freedom.
The assumption here is of course that people have a real choice in the matter. If they are forced in some way to renounce their rights, then society and the state still have a duty and a right to intervene in order to enforce respect for people’s rights, even if these people explicitly state that they don’t want this intervention. A masochist who freely chooses to be a masochist – and isn’t suffering from a mental illness or from sadistic pressure – should be free to have her rights violated. A dwarf or a prostitute who has no other means of income than dwarf-throwing or commercial sex respectively is clearly forced and didn’t freely choose to have her rights violated, in which case society has a right to intervene, even if that person opposes such intervention. But of course she will only oppose the intervention if it is merely a prohibition: if the state merely prohibits dwarf-throwing or commercial sex it will make things worse. The person in question loses her income on top of her rights and dignity. Hence, intervention should also mean the provision of an alternative income not implying rights violations. Lack of income is also a rights violation, and you can’t solve one rights violation by violating another right. You can’t free someone from sexual slavery by taking away her income.
The obvious difficulty here is to ascertain whether people’s renunciation of their rights is a free choice.