從銀行業務角度來看，瑞穗銀行可能因為什麼原因..

看到一份報道 Bitcoin Exchange Mt. Gox Asked by Japans Mizuho Bank to Close Account

提到了瑞穗銀行要求 Mt. Gox 關閉他們在瑞穗的銀行賬戶。

Mizuho Bank official: “Well, this is a casual discussion but as we’ve been saying many times we want to close your account.”

Mark Karpeles: “I discussed with my lawyers and they said we don’t need to close it, so we’d like to keep it.”

Mizuho: “Closing the account is actually our demand. We made various judgments and also have a certain policy. It’s possible we will forcibly ask you to close your account. As our headquarters also told you, if possible we want you to close the account voluntarily, but the chance isn’t zero that we will leave you no choice.”

Mr. Karpeles: “I want to know why you’re asking us to close everything. … I need an explanation.”

Mizuho: “There’s a collection of various issues.”

Mr. Karpeles: “Your approach has been very forceful and to be honest it’s rude. That makes us unwilling to take a cooperative attitude.”

可是瑞穗沒有說具體的原因，只是說關閉賬戶是因為“There’s a collection of various issues.”，從銀行業務的'角度來看，這些 issues 可能是什麼?

另外提供一個對話來提供線索：

In the months before Mt. Goxs collapse, the bitcoin

提到了 unmanageable volume of money transfers ，這裡的「無法管理數量的資金轉賬」會對銀行產生什麼負面影響嗎?