I think these might be "Jews for Jesus" sometimes called "Messianic Jews". If not, it is just a form of Fear of the Lord. Old testament Jews would not write the entire name Yahweh. They would leave out the vowels. Someone correct me if I'm wrong.
Considering this, my question is, since the incarnation, is this form of not writing God's name still a mandate? I don't believe so. I've never seen any of them write J*S*S and He IS GOD.
Just MHO!
Good point. Thanks.