You can't hack a inventory of a player. If he could he wouldn't need to go and scam.
If you drop stuff in your house and invite people you don't know, then it's your fault for being scammed.
Just report hackers, Staff will see it. We don't need to be warned because everyone should know not to try to trade with someone that isn't your best friend. It's not safe in your house if you invite people you aren't best friends with, because once again staff won't/ "aren't allowed" to make a system to lock dropped items in your house.
This thread should be closed, you encounter the hacker again then report him or feedback about him. Staff can take care of it that way.