The security levels refer to using a Hostiles file. These hostiles files block out known BOTs of varying types including Spam-bots, Browse-bots and Download-bots. There are also other blocks of certain anti-file-sharing groups and others. There are two hostiles files; strong and light. Light is a smaller file and suits the needs of most people. Strong is much larger but may also contain a lot of out of date listings. Some people would prefer not to take any chances and opt for Strong. None refers...