Tony, thanks for your comment. On the hit rate, you are correct, it does increase it, but only minimally. Most commonly, the web-crawler visits the website once. We may visit another time for validation purposes. These few visits are unlikely to increase their stats significantly. But this is something to keep in mind for future research on these issues.

The one concern I have is that if the crawlers mentioned in the article are visiting these illegal sites, doesn’t that increase their hit rate and encourage more offenders to either contribute to existing sites or start up their own? Both activities that would risk more child exploitation happening.