carseat nazi
Someone who is so uptight about carseat advocacy that they come onto your post or blog and continue posting the same stuff over and over even though they know that you don't care about anything that they are saying. They think they know all there is to know, and it has to be their way or it's not right and you are wrong!
Someone posts a cute picture of their 10 month old in a carseat on a board on a website. Carseat Nazi's come in and tell her that she should ERF (extended rear face) until 2 and 40lbs because that is SAFER, and if she doesn't agree, then they tell her that she is an idiot.