So happy about this. On our last flight on Southwest, my mom's laptop screen was actually bent slightly backwards because the guy in front of her reclined his seat so quickly. Her screen was open and underneath the seatback tray lock leaning at about a 115 degree angle. This was during midflight, about 1.5 hours in. When he whipped his seat back, her computer screen got pressed down from the lock and then actually bent a little backwards from the force. She had to hurry and push his seat back up and get her laptop out from under the tray lock before it broke. He looked back with a what the heck face, but I don't know bud - maybe don't whip your seat back without warning?
I think it's common courtesy to check and make sure people don't have drinks, laptops, etc on their tray before swinging it back. Maybe even a quick, "Good afternoon, do you mind if I recline my seat a bit?" would go a long way.