How can I short the optical networking and cloud computing sectors?

There is a huge bubble in these two sectors and I don't know how to short individual stocks. Is there a mutual fund or active etf that shorts these sectors?|||For cloud computing, you would short Amazon, Google and salesforce.com as those are the current leaders in the field. As for optical networks, that would be the phone companies like AT%26amp;T, Verizon, etc.