Keyboard Gangster

Customer who will not enter a store in person, or even pick up the phone, but will not hesitate to trash you, your performance or your company to Hell and back by email or online review. IF any in-person or telephone contact is made, a Keyboard Gangster will go directly to your boss and trash you there as well. Could also be described as a crossbreed of a coward and a Troll.

You can try and get ahold of him, but he won't pick up. He's just a Keyboard Gangster, yo. Just forget about him.