Many of our German and Polish users have probably experienced a great deal of frustration getting verified with Mt.Gox, as Germany and Poland both issue an identity card which includes a person's current address. Unfortunately, because we must also follow American and Japanese rules, we also have to ask for separate proof of residence documents.
Can you please explain what the Japanese rules are, because this is clearly inconsistent with US rules.
The US customer identification requirements are not to acquire copies of specific documents, but rather to verify the information that you're given.
For example, is the address and phone number valid? Did the customer receive mail that you sent to that address? Is the information consistent, ie does the telephone area code match the address given? If the customer claims to have lived at the address for 3 years, can you verify that with a third party (eg a telephone directory)?
Photocopies of ID cards are generally not sufficient or required, because someone could submit a copy of someone else's ID. If a customer walks into a bank in the US and opens an account, a bank employee will look at the photo ID to make sure the customer is not using someone else's ID, but they don't need to photocopy it.
In the event that you are not able to verify a customer's information, you do have to return their money. You don't have to do business with someone, but you can't just take their money and keep it.