Does Intel also enforce such a rule to office workers, like Samsung does? I can partly understand the desire to control accidents in manufacturing environments, but we're not exactly at such a place. Samsung's rule is applied to all workers regardless of campus, including the inside of a building consisting of mostly software engineers and office workers. It almost feels like the company wants social equality among employees or something.

Intel's rule was against corporate espionage, so probably? They eventually allowed phones with the cameras drilled out.

All Asian Fabs pretty much ban all smart phones - you have to leave them outside and/or you have to use a "dumb" phone. Laptops, USB drives, etc. are absolute verboten as a vendor or contractor and usually employees as well who have to smuggle them in to get work done. If you violate these bans as a contractor or vendor, YOUR ENTIRE COMPANY can be banned from doing business indefinitely.