Addendum: What they don't seem to realize is that Anti-Christ wants souls, not bodies.
The Protestants, already deceived, think that they will know the anti-Christ on sight: "I won't take the Mark of the Beast! I'll stand up for my faith! They won't put a microchip in me!" Luther already put a microchip into them.
I actually think the Mark of the Beast was Lumen Gentium, since this document defines the religion of MAN -- 666.
The mark in the "forehead" means that people have accepted idolatry in their minds. The mark in the right hand is symbolic because the hand in Biblical terminology represents the way that Christians are caught -- Jesus catches the apostles in his hands after they walk on water. And the left hand is associated with witchcraft, while the right is associated with God.
Since Lumen Gentium tried to destroy the Church Militant and made all religions more or less equal, there is no way to convert anyone to this fake new brand of Catholicism, no way to take them in your HANDS. Those staying in Vatican II thus have a marked, or ineffective and lame, right hand and can't catch any fish.
Just my theory. I may not be right, but the idea that the mark will be a bar code or microchip is a load of horse caca fit only for Protestant conspiracy-theorists of low degree. This is rich symbolic language we're dealing with.