security is one of the most important thing to prevent your data from hackers. Some of the ways to your data from hackers include using hardware wallet, avoid sharing your private key with people and be careful with hackers
If we share the private key it's called suicide, because that private key is very important for the security of our wallet. So we must be more careful in storing our wallet's private key.
Ofcourse, private keys are your access to your wallet. If someone has it he can steal your coins and transfer to different wallets he has access to. Always be careful if you login and avoid any risk as much as possible. Some weeks ago I wrote a detailed article about security risks, maybe you can gain knowledge:
https://bitcointalk.org/index.php?topic=4907130.msg44198076#msg44198076