How to move "block-user" to a different region?

I want to move my user block to the left bar, but it shows up in the header region by default. When I check my block list, there is not a block called "User". But the source code shows the class name as block-user. Does anyone know how to move this?

Thanks in advance.

p.s. I tried moving "User Log In" block. The "block-user" didn't get moved, so this is a different block.