Leviticus, the last time I checked, is in the Old Testament. A Christian, by definition is one who believes in Jesus Christ as Lord and Saviour, and therefore is saved by this faith, and the laws of the Old Testament do not apply. I would wonder if this person who posted the passive/aggressive Leviticus passage follows ALL the Old Testament laws, including not eating pork, shellfish or even cheeseburgers.
I am not a fan of tattoos. I just don't like them. But I have no problem if others want them. It doesn't bother me, it is none of my business. But as a Christian, I find "drive-by" shootings of holier-than-thou instructions truly offensive. If someone pulled that kind of nastiness on my FB page, I would quote back this Bible verse: "Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment. And the second is like unto it, Thou shalt love thy neighbour as thyself. On these two commandments hang all the law and the prophets." There is nothing in the New Testament that prohibits tattoos, but that FB comment doesn't exactly "love thy neighbor as thyself"!"