Growtopia Staff replied:
The only way for someone to gain access to your locks and inventory is to be logged in with your password.
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It is simply not possible to "hack" an account and steal a password in Growtopia, here is why:
* Growtopia is a MMO that is server based. Your IP address is never made public to other players, so they can't directly attempt to hack you at all.
* Passwords are NOT stored or logged at all. We only store salted hashes, not passwords. This means EVEN WE don't know your password, and can't get it. This means even if someone hacked the Growtopia server and stole our entire database (this has never happened), they STILL wouldn't know your password.
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So how did someone logon as you? Probably one of the reasons below:
* You got tricked into giving out your password to a player or website that promised free stuff if you did (these are ALWAYS scams, they just log on as you and steal your stuff)