broke.rb

class Foo
  private
  def self.bar
    puts 'I broke your ruby'
  end
end

Foo.bar # I broke your ruby

class Foo
  class << self
    protected
    def bar
      puts 'hello'
    end
  end
end

Foo.bar # broken
Foo.instance_eval("class << self; self; end").send(:public, :bar)
Foo.bar

class Foo
  class << self
    def barbaz
      class << self; self; end
    end
    protected
    def bar
      puts 'hello'
    end
  end
end

Foo.barbaz.send(:public, :bar)
Foo.bar

class Foo
  class << self
    protected
    def bar
      puts 'hello'
    end
  end
end

Foo.send(:public_class_method, :bar)
Foo.bar