Major search engines cache your web pages. You must make your web pages look flawless on search engines' caches or you will miss a big proportion of search engine traffic.
Hotlink protection is commonly used to prevent copyrighted images from being used by somebody else. This feature also prevents images from being downloaded by cached pages. As long as your pages have good content, searchers will be interested in your site. However, texts which look good against background images may not be visible when hotlink protection prevents the background images being downloaded. When this happens, searchers cannot see anything on the cached pages, so they will go to other sites suggested by the search result.
Scripts, such as PHP and CGI, can be disabled by any websites other than their own. This is a good idea from the point of view of security. But, if you disable scripts from other websites, they will not be executed from cached pages either. Make sure this won't cause serious problems when viewing cached pages.
© January, 2005