从银行业务角度来看，瑞穗银行可能因为什么原因..

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

提到了瑞穗银行要求 Mt. Gox 关闭他们在瑞穗的银行账户。

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.”

可是瑞穗没有说具体的原因，只是说关闭账户是因为“There’s a collection of various issues.”，从银行业务的'角度来看，这些 issues 可能是什么?

另外提供一个对话来提供线索：

In the months before Mt. Goxs collapse, the bitcoin

提到了 unmanageable volume of money transfers ，这里的「无法管理数量的资金转账」会对银行产生什么负面影响吗?