Those who use Google, which according to reports is just about everybody;-) will know that they store a cached version of all the pages that they index. This can be useful if a site is down for any reason or the particular article or page has been moved.

However, it does cause a problem with privacy for web sites that offer private groups, or forum areas. I know of quite a few that have beencaught out by Google showing their members private messages, and in some cases business sensitive information to anyone who happens to stumble upon the page in some search results.

If you believe this could be a problem on your site then there is a solution. Just set up or edit your robots.txt file (this should be in the root directory of your web site) and add the following line:

<meta name=”googlebot” content=”noarchive”>

This will prevent Google form caching any part of your site.

Don't worry, there is no impact on your search rankings or the number of pages of your site that get indexed. In fact there really is very little benefit  to be had from letting Google cache your pages, so I would recommend making this a standard part of any web site setup.