Hi BHW, I have been using the Moz free version of Open SIte explorer and noticed a competitor website has potentially begun blocking the spiders for Moz. Because I tried with a different tool and caught some new links. Perhaps Moz just has not scraped the other links yet? My questions are: - How common is the practice of masking your backlinks? Is the main method to just keep a list of the most common IP addresses for known tools and just block those on the server? - What would you guys recommend to check backlinks? Free and Paid Thanks!