An interesting article for those interested in exploring the dark side: https://www.securityweek.com/meet-kilos-new-search-engine-dark-web
Obviously, one should use the appropriate cautious measures.
And before I get berated by my colleagues, if one does not explore, we would not have reached the Moon without breaking a few eggs on the way. So explore with the appropriate safeguards, but obviously this tool can be used by legitimate organisations as well for intelligence and tracking purposes as well.
"Integrity without knowledge is weak and useless, and knowledge without integrity is dangerous and dreadful.