Not all humans inherently deserve rights just because they are human. Think of people like Hiter, Jeffrey Dahmer, and the dozens of other evil people. No one would reasonably think they deserve sympathy, because of what they chose to do.
If your evil enough to commit such a heinous act as child rape, I don't see any legitimate reason why that person should deserve any sort of sympathy.
Subconsciously everyone agrees on this to some extent. Look at prisons, (depending on the crime) they remove your right to vote, own a gun, even walk outside, and have certain jobs.
The reason I believed my take is controversial is because of how I think those pedos would lose their rights. I believe people as evil as them aren't people at all. They are simply containers of flesh with a human face, and should be seen as such. I have no issue with the idea they should be used as slaves and test subjects. Arguably this would actually benefit humanity (especially in terms of medicine) because now instead of risking the lives of innocent people like doctors or everyday Joe's, we could use them to see if the experimental drug has any side effects. Honestly, what are they going to do? Revoke consent? I wonder of the child they raped got that same privilege...
I'm sure this goes without saying but the person would have to be caught red-handed with undeniable proof to be subjected to this
Rights aren't, and shouldn't be, all or nothing. Criminals, for instance, forfeit certain rights depending on the crime and the jurisdiction. Often they forfeit the right to freedom and end up in prison. In some places, for some crimes, they might even forfeit the right to life and get executed.
But the important things is we have a system for determining what those things are. If, as with your example, we said pedophiles have zero rights, that would mean that anyone would be free to kill them, to steal from them, to torture them, or whatever. That doesn't seem like a good move for society, especially given the potential for abuse.
That's literal outlawry: being put outside the protection of the law. Anyone being free to kill an outlaw is a feature of outlawry, not a bug.