To stop the before filter chain you use throw :halt with a few options:

        # halts the filter chain and calls filters_halted which you can override
        # in your controller to specialize it.

        throw :halt

        # halts the filters and calls the method named after the symbol:

        throw :halt, :other_action

        # halts the filter chain and returns the result of the Proc being called

        throw :halt, Proc.new{ |c| c.redirect "/foo" }

        # halts the chain and returns whatever is in the string

        throw :halt, "<h1>You don't have permissions dude!</h1>"

        or even render templates:

        throw :halt, render 'foo'
        throw :halt, partial 'foo'