How is this ok?

I actually took some time to study Ashura this year and came to appreciate the tradition of remembering the death of Hussein. Then I was reminded of these types of images...

Does anyone really know how widespread these types of self-mutilation ceremonies are?
There are tons of them online from Shia communities worldwide.

So my question is, how does someone justify forcing a child to participate in a bloodletting ceremony?
A baby?

Its just not ok.