Description
Hides the block even if it is not "empty".
Is somewhat an opposite to touchBlock().
Consider a block (a 'edit' link for example) that should be visible to registered/"special" users only, but its visibility is triggered by some little 'id' field passed in a large array into setVariable(). You can either carefully juggle your variables to prevent the block from appearing (a fragile solution) or simply call hideBlock()
