Sounds strange that a bank would host its website on a shared Ip address.
They didn't.
To clarify: the blogger set his domain to point to the bank's IP address. The automated domain blocking system resolved his domain and blocked "its IP" without confirming that the IP actually belonged to the targeted site.
And best part is when Russians were blocking a blogger's web site based on IP he switched his IP to a bank's web site and thus the bank's IP was blocked automatically :)