There are a lot of conversation in this forum about Google's duplication content filter. Which other filters exist or you think might exist in the future? 1. filter for much links from unrelevant sites 2. filter for sites with much links from blog comments, link farms etc. various 'link schemes' 3. filter for sites which acquire too many links too quickly 4. filter for sites which acquire too many pages too quickly - generated content 5. scraper and duplicated content filter Do you think other types of filters exist nowadays? Could you think of other types of filters which will exist in the future?