Someone tracked down a young female employee on social media from the full name printed on her name tag, and they began stalking her. A customer also threatened to expose an employee's name on the internet.

Just a suggestion but how about not printing their full name on the name tag?

"Speed" on my name tag is sufficient. My manager knows who that is. "Speed Racer" is unnecessary.

We should all use alias to protect ourselves.

Have the stalker and the person making threats been arrested and charged? If so was it reported and where?

Last name only on tags should be pretty simple...

Last or first names only.