Well it’s not something Evangelics do...
I recall as a child when I saw people with a black cross on their forehead I thought they were against Jesus so they took a black mark on their head to show that.
Well, there is Scriptural precedent about receiving a mark on your forehead and which side you're on.
I could see people getting duped into taking it with a *Do it this way and make it permanent. Show the world all the time who you're loyal to.*