TLDR; in some jobs, you can't have social media accounts.
I have some contact with cybersec in Europe and it is very common that cybersec professionals in gov and mil positions do not have any social media accounts under their own name, and certainly not linkedin. Social media makes you too much of a target and reveals too much about your org. When promoted to a public-facing position the person then suddenly "appears" from nowhere and the media profile has as little information as possible. Real professionals use those accounts only from designated computers, and if you are high ranking enough (head of...) in fact never use them at all, but rather have someone else using them for you. All in the name of keeping your own actions and locations away from the curious.
Knowing the organization exists and knowing that someone specifically works the organization are two different things. In fact, this is the defining characteristic of any secret organization (governmental or otherwise: CIA, Stasi, KKK (in the 50s)...) that wants to project power: we exist, we are everywhere but you don’t know who we are.
I have some contact with cybersec in Europe and it is very common that cybersec professionals in gov and mil positions do not have any social media accounts under their own name, and certainly not linkedin. Social media makes you too much of a target and reveals too much about your org. When promoted to a public-facing position the person then suddenly "appears" from nowhere and the media profile has as little information as possible. Real professionals use those accounts only from designated computers, and if you are high ranking enough (head of...) in fact never use them at all, but rather have someone else using them for you. All in the name of keeping your own actions and locations away from the curious.