If you are a Catholic, you might take a look at “The Microchip is the “Sign” of the Beast of the Book of Revelation” at http://markbeast.blogspot.com.
Not that being Catholic is relevant to this subject, and I have NO clue what Catholics of any stripes believe, and it does not matter what your http: site claims. Those that receive that 'mark' do so willingly, they do not know what the mark is.... now if a supernatural being shows upon this earth how would you know who that entity was. The 'mark' is about counting over a very long period of time..... how many know how to count that number???
The 'mark' is accepted because of lack of knowledge as to what literally the 'mark' is, and who will willingly accept and receive it. It is what you believe and who you believe, not a literal object that is visible.