I have been reading about Coop, LV and ReceiveLinks, and quite a few people claim that they lost rankings because they used Coop, LV, ReceiveLinks or any combination of these three. Is this a legitimate claim or not? Also are these link networks helpful, harmful or neither? If neither, then is there so called "right way" to use these networks such as - Limit number of links displayed on each page - Not using your main site(s) to display links ...?