If nothing else, it's probably safe to assume that someone like Mark Zuckerberg or Larry Page regularly get emails or other messages saying things like "im gunna go to ur house nd kill ur dog and ur hot wife"
Law enforcement doesn't have the resources to investigate every one of these, absent a credible threat of it actually happening, so corporate security / executive protection exists to, well, investigate.
Considering the necessary exposure the president has, he might be even more secure.
Personal security for CEOs (never mind billionaire CEOs) is hardly anything new. If I were Mark, received the amount of hate/threat messages he does, and had a young daughter, I'd do everything short of hiring the 82nd Airborne to follow me around.
https://www.businessinsider.com/how-much-silicon-valley-ceos...
Taylor Swift once said "I don't have security to look cool. I have security because people want to take me home and chain me to a pipe in their basement."
TSwift isn't even a billionaire.
https://en.wikipedia.org/wiki/Law_Enforcement_Officers_Safet...
For some positions, the ability to carry concealed was mandatory (e.g. the CEO's driver/bodyguard). Related aside: the CEO I'm thinking of wasn't allowed to drive himself in order to avoid any stock hits if they whapped into a kid running into the street after a ball (or what have you).