Sealed Lock Doesn't Work?

This is exactly what i was thinking, once the "hacker" has your account they are you. So it will be easy for them to send in a request on unlocking the item.

This is were nexon needs to add a new batch of secret questions, when you file a ticket to unlock your item include 2/4 right secret answers.

Or they could use a separate pin lock system. Anyone going to lock it in the first place would be smart enough to actually memorize those pins.