Most online child pornography is not hidden nor encrypted in any way. Just search Bing; you can get the keywords from wikipedia then follow bing's suggested queries.<p>Microsoft claims that they remove child abuse links from their index upon notification by such organizations as the National Center For Missing And Exploited Children but clearly they dont.<p>There are some imagehosts that either have no way to locate their images from their homepages, or whose search forms dont list child pornography in their results, however its all indexed by bing.<p>The videos at the filesharing services commonly have obvious or easily brute-forced passwords. There arent that many different passwords in widespread use; I expect a list of the 100 most common passwords would decrypt 99% of the videos.<p>The passwords and lightly obfuscated links are mostly posted to dead forums. If you operate a forum yourself the simplest way to defeat this is to disable posts in threads older than a month or so.<p>If you want to find these posts on your server look for a large number of occurrences of the word the word "password".<p>I have even seen this at last.fm.