OpSec (Operations Security) is the act of protecting your identity during an investigation.
Beforehand, the threat model must be determined: against whom or what do we want to protect ourselves and why.
This threat model will then enable us to define the protection measures to be implemented:
use of a sock puppet account (online identity you use only for an investigation).
use of a VPN (Virtual Private Network)
...
It is an illusion to seek to secure oneself online without having defined the risks linked to an investigation in a reasoned way.