Stack Overflow is given the lowest rating (class E) in terms of user rights. (For reference, even Google has a class C rating.) Here are the worst points taken from SE's privacy policy:
* This service allows tracking via third-party cookies for purposes including targeted advertising.
* You agree to defend, indemnify, and hold the service harmless in case of a claim related to your use of the service.
* This service forces users into binding arbitration in the case of disputes.
* Many third parties are involved in operating the service
* The service may use tracking pixels, web beacons, browser fingerprinting, and/or device fingerprinting on users.
* Blocking cookies may limit your ability to use the service
* You waive your right to a class action lawsuit
* This service can share your personal information to third parties
* The court of law governing the terms is in a jurisdiction that is less friendly to user privacy protection.
* The service can sell or otherwise transfer your personal data as part of a bankruptcy proceeding or other type of financial transaction.
* The service uses your personal data to employ targeted third-party advertising
* This service retains rights to your content even after you stop using your account