> Literally no one cares that you watch excessive amounts of fetish porn [...] or sell a few grams of cocaine on the side

Actually such people are great targets for blackmail, to be used in espionage and interference.

https://en.wikipedia.org/wiki/Recruitment_of_spies#Recruitme...

It's completely naive to think that only serious wrongdoers are the targets of SIGINT, rather than simply anyone with usefulness to state motives.