Use an authenticator app (like Google Authenticator or Authy) rather than just email verification.
In your Roblox settings under the "Security" tab, click "Sign Out of All Other Sessions" to kick off anyone who might be logged in.
Hackers use these lists to gain access to accounts, steal Robux, and trade away rare limited items.
Since many people reuse passwords, attackers will try these same credentials on Discord, Gmail, or bank accounts.