Recording and intersecting search trails is covered by this patent:
https://patents.google.com/patent/WO2005069161A1
The rationale is here:
https://www.jinfo.com/go/blog/2505
Recording and intersecting search trails is covered by this patent:
https://patents.google.com/patent/WO2005069161A1
The rationale is here:
https://www.jinfo.com/go/blog/2505