This has nothing to do with privacy! Criminals have their techniques and methods to protect themselves and their “businesses” from discovery, both in the real world and in the online world. Even in a complete absence of privacy they would find a way to hide their stuff from the police - at least for a while.
In the real world, criminals (e.g. drug dealers) also use cars, so you could argue, that druck trafficking is a side effect of people having cars…
Never been happier to see some cookies (I can delete or block).