People have started putting "Er" before their names on Facebook/LinkedIn to tell the world they're engineers.

Very "Ew" behaviour.

I think doctors put "Dr." before their name because it might be beneficial to spot them in emergency situations. And, you can't put Dr. before your name if you haven't completed your education. Because, you don't want to treated by a half baked doctor. Engineers can gather the required skills even in basements. And, they don't deal with lives so don't see the point of putting "Er." before names.