its not the same as your analogy because people who have lite wallets
are still posession of their own "gold"
the "gold" doesnt belong to the "warehouse" node just because you maybe using a litewallet
i have a lot of coins stored in a multibit wallet i use when im travelling but theyre not any less secure than coins stored in my full client node , AFAIK theyre both bulletproof provided the systems dont get compromised by malware or keyloggers or whatever
It's not about who "owns" the gold; it's about whether the gold is actually there or not. Obviously bearers of a gold certificate are considered to be "owners" of the corresponding bar, but that is not a guarantee that the gold actually exists. Your multibit wallet has to get transaction data from a full node, and if that full node says your address has funds when it actually doesn't, you may be tricked into making a bad deal. This isn't about having an insecure private key; it's about nodes falsifying transaction history. I don't need your private key in order to create a transaction that appears to send you funds; if you don't have a full copy of the transaction history to verify it, you won't be able to tell a bogus transaction from a legitimate one. If everyone comes to rely on the few "trusted nodes" like bc.i, and a malicious state takes over these nodes, they can create whatever transaction history they like and people like you will not be able to recognize the difference.