Cloaking is practically a black hat SEO method that presents a totally different content rather than the content it should present. So how can cloaking be an ethical SEO method?

Consider a full Flash site with all the content embedded on it. How can search engines crawl the content on your Flash-based site? The solution is simple–cloaking. By utilizing the CSS method of making a block invisible, you can display your Flash site as well as the content you intended to get indexed on search engines.

Consider this Flash site with cloaked content: Wideout Technology Services, Inc.

The content you see is embedded on Flash itself but I did include the same original text within the HTML and did use CSS to hide the text to the actual audience. Now, try viewing the source code (View then Page Source or CTRL+U on Firefox). You will notice the original content on the HTML itself and if you look more closely, you will see the context enclosed in this block:

<div class="noflash">
 <h1>A True Global Workplace</h1>
 <p>We believe that a business should not submit to geography.
  ...
</div>

And in my style sheet goes the trick to hide the text content to browsers but not to search engines and text/screen readers:

.noflash {
	display: none !important;
}

For the conclusion, you can ethically use cloaking to your site’s pages provided you are still showing the same original content to both search engines and your actual viewers/users.