If Facebook is built on a blockchain network, will 50 million users still leak information?

Traditional centralized database is not secure
The traditional centralized database is guaranteed by the service or product provider for its data security.
For example, Facebook is responsible for all security on Facebook.com. However, just today, Facebook, the world’s largest social networking company, was exposed by a data scandal. Its 50 million user data data was used illegally by third-party data analysis companies. The stock price fell by 6.8% on Monday with a market value of $36.7 billion.

Why is it dangerous to centralize the database?
First, the centralized database is likely to be attacked.
If the centralized database contains some sensitive information, it may be attacked. After successful hacking, hackers will get a lot of important sensitive information.
Although the distributed network database will also be attacked, the risk/reward rate of attacking the distributed database is far lower than that of the centralized database. Hackers are more difficult to attack than centralized databases.

Second, centralized databases have security risks.
You don't know if the centralized database has internal ghosts, or the vendor uses your data to deal with you. Maybe, you trust your supplier, but no one can guarantee that there will be no leakage, ensure that your data is 100% safe, and that service providers will not abuse your information. Isn't it?
The Facebook data scandal, for example, was his third-party company, Cambridge Analytica, who violated Facebook's rules and used 50 million users' personal data to create archives and targeted promotions for these people during the election.

Blockchain security features
The blockchain uses a decentralized database and uses hashing and algorithms to ensure data security, bringing a whole new paradigm to network security.
Decentralization means that no party needs to be responsible for security. Security is created collectively in the network. Security is jointly granted by participants.
Hashing and algorithms allow users to use the process without trusting conditions, without having to endorse it, without trusting any company, trusting anyone, trusting any third party, and code is the law. You only have to believe in the mathematical and computational principles of blockchain construction. Of course, this seems very avant-garde, but it brings new possibilities.

Why is the blockchain database more secure?
The blockchain creates a huge redundant network, and the entire network remains secure regardless of whether or not a few nodes in the network are shut down.
However, we must have enough nodes to protect the network, otherwise it will increase the risk of attack by 51%.
For hackers, getting a password or private key is very difficult in a decentralized network.

If the Facebook social network is based on blockchain network construction and the data analysis algorithm is also based on blockchain design, then the data will be more secure without the need of a third party. The code is the law and expects the security features of the blockchain to shine in the future.