Answering your question to my satisfaction is difficult from a single source, but here are some key points and source links that may help: * "Can Blockstack co

Answering your question to my satisfaction is difficult from a single source, but here are some key points and source links that may help: * "Can Blockstack control my data or ID when I use it? No. When you're using a Blockstack client you control your data and ID with a private key. This private key never leaves your device and is meant to stay on your laptop/phone. As long as no one gets access to your private key, no one can control your data or ID. When you use Blockstack, by design, your private keys are never sent to any remote servers." [https://blockstack.org/faq https://blockstack.org/faq] * "The main difference between blockchain identities and accounts on any other service is that blockchain-based systems have strong ownership. Blockchain identities can't be confiscated by any service because the system defines ownership according to ownership of public-private keypairs, just like ownership of coins on Bitcoin. This is in direct contrast to Twitter or Facebook usernames, which could be confiscated or censored at any time by the respective companies that they belong to." [https://blockstack.org/posts/blockchain-identity https://blockstack.org/posts/blockchain-identity] * "Identity is user-controlled and utilizes the blockchain for secure management of keys, devices and usernames. When users login with apps, they are anonymous by default and use an app-specific key, but their full identity can be revealed and proven at any time. Keys are for signing and encryption and can be changed as devices need to be added or removed." [https://blockstack.org/intro https://blockstack.org/intro]