I remember listening to a podcast where some guy was describing how the FBI (I think?) had a map of the 5 most frequently contacted phone number and the average

I remember listening to a podcast where some guy was describing how the FBI (I think?) had a map of the 5 most frequently contacted phone number and the average rate of contact for those numbers for all landline and cellphone users in the early 2000s. They were able to de-anonymize burner phones by mapping what numbers they were contacting, who those numbers were contacting and who the 2nd hop numbers were contacting. Given that this was the technology 2 decades ago, I’m going to guess that similar behavioral fingerprints have been collected for all sorts of data. I wonder if it’s possible to fingerprint someone from the frequency of the top 5 websites someone visits and the time at which they are most actively browsing a website. Edit: I found the podcast from my notes. Episode 265 of the James Altucher Show