There is no way to save those people without destroying privacy.

I disagree. Legalizing prostitution and fighting the social stigma would prevent many of those crimes.

If you criminalize a service that will always be in demand, you won’t kill the market - you’ll just turn it into an unregulated black market run by criminals, who are much less inhibited than legal employers to use any means at their disposal (even threats and violence) to maximize their profit.

The exact same thing happened during the prohibition.

But if you have a legalized market… using threats and violence to force people to perform i.e. call center work is much less common.