You agree to give up your data in return for services. Yahoo mail, or gmail for that matter aren't actually free. You are trading your data for a service.
I don't understand. You believe you have the right to have no records of yourself written anywhere. You believe it is impossible to contract away this right. You've given HN an individual identifier for yourself, and also furnished your political views (a specially protected category under the GDPR) to its database.
Aren't all your comments proof of Y Combinator's human rights violation against you? Shall we have HN shut down and its operators jailed? Obviously this isn't the world we live in, but isn't it the one you're arguing for?
Maybe you can't give permission to have data treated carelessly, but it seems absurd to say you can't give permission to have data collected at all. Opening an account with Yahoo is surely consent to let Yahoo have a record of that account.
Some rights, but not all rights. You cannot (in any country I am aware of) contract away your right to life, nor turn yourself into a slave in exchange for your debts being forgiven.
The latter used to be possible, if I understand serfdom correctly.
Question is, should data rights be alienable or inalienable?
If you're talking about what rights you should have, that's fine. Currently, however, there is no defined right in the US such that service providers like google, Facebook, etc can't make use of the data they acquire from you. If you consider data on you to be more valuable than the service provided, don't use the service.