Cloud Computing can be evil because-
1) Most browsers are owned by for profit corporations . Corporations can be evil, sometimes
And corporations can go bankrupt. You can back up data locally, but try backing up a corporation.
2) The content on your web page can be changed using translator extensions . This has interesting ramifications as in George Orwell. You may not be even aware of subtle changes introduced in your browser in the way it renders the html or some words using keywords from a browser extension app.
Imagine a new form of language called Politically Correct Truthspeak, and that can be in English but using machine learning learn to substitute politically sensitive words with Govt sanctioned words.
3) Your DNS and IP settings can be redirected using extensions. This means if a Govt passes a law- you can be denied the websites using just the browser not even the ISP.
Thats an extreme scenario for a authoritative govt creating its own version of Mafiaafire Redirector.
So how to keep the cloud computer honest?Move some stuff to the desktop
How to keep desktop computing efficient?Use some more cloud computing
It is not an OR but an AND function in which some computing can be local, some shared and some in the cloud.