In a thread at Google Groups, a new topic has surfaced and it is on, how Webmasters can hide their content from Google. It also has a take on how Google interprets these steps and what it has to say about them. According to Search Engine Roundtable there are four methods through which a Webmaster can easily hide his website's content from the search crawlers. There is also the response of Google that goes hand in hand with these steps.

• Javascript-only-Navigation: It seems that this method is fruitless in its nature as it in no ways seems to deceive the search crawlers and therefore would not create any ranking concerns.
• CSS-Enhanced Navigation: This method would not levy any penalties against a Webmaster, as long as the intention of using it isn't to deceive the search engine crawlers. It can also be considered as a good move keeping accessibility in mind. However, if a user is able to able to follow a link without CSS or Javascript then even the crawlers can follow the link as well.
• Hidden Links via Positioning/Color, for Design/Accessibility: This is a dangerous road for a Webmaster to take. As long as 'Skip to Content' isn't taken as a deceptive step, till then a Webmaster is safe. However, if penalized, then the consequences can be too harsh. So better avoid this one.
• Hidden Links with No Mention of Accessibility or User Value:
  This is one step that might also be taken as a 'suicide' step for a Webmaster. This method can easily termed as 'deceptive' by Google, stating that this step was used with an attempt to deceive the search engines. Because, these links would only be visible to crawlers and not the users. A penalization could mean a complete ban from Google's indexes.