The entire practice of Judaism — everything we do from covering our heads to washing our feet — is based on the Jewish texts, aka the Midrash. If it is written in the Torah, the Talmud, the wall above a urinal under the Wailing Wall, whatever, it is LAW.
We just have to be happy that our ancestors chose these texts and not something else like, say, the Many Adventures of Winnie-the-Pooh. Because then we'd be running around with balloons tied to our waists binge-eating honey.
So, anyway, somewhere among the many tomes it says that we should not desecrate our bodies. Tattoos, piercings and any other trappings of the modern urban youngster are out (aunt Ida's grapefruit-sized diamond earrings from the miracle mile are somehow perfectly fine, however).
Ah, you say. But what about perennial benchwarmer Gabe "the Babe" Kapler and his Jewish tattoos? After all, G-d couldn't be opposed to that, could he/she/it? (Seriously, don't smite us.)
If you ask the traditional leaders of the community — your Jewish mother — the answer to that question is "Yes, yes G-d is very offended by your tattoos and I hope you're happy now that you've ruined my life. Now finish your brisket before it gets cold."
If you ask G-d? Well... wait, you talk to G-d? Seriously? OK, then. Please let the Almighty, blessed be he, know that we would like a hundred-million more visitors for our website, our own two-hour program on Thursday nights following "The Office" and a new shiny red bicycle.