User selectable cap means sybil attack. Again, nobody is answering my questions here.

What will BU do to stop my 2000 nodes acting to create the illusion of that the network wishes for very large blocks.

Actually, my Sybil attack can go something like this:

1) Vote for 1.5 MB blocks
2) Check how many nodes I have killed with the increase
3) Vote for 2MB blocks
4) Check how many nodes I have killed with the increase
X) Keep doing until I am the network of nodes. Fill up the blocks and start pushing out the Chinese miners as well.

Incremental Sybil attack, cheap and easy to pull off.