[Plutarch]

Tattoos -- a series of short, dark, parallel lines -- had been placed to treat his arthritis as an early form of acupuncture.

More speculation presented as fact.

[Sax]

Actually it was his UPC symbol so the aliens who placed him there could check him out of their inventory.

Did they find his tinfoil hat?

[Publius Scipio]

Yes, I'm sure it was merely a coincidence that the tattoos happened to overlay the accupuncture points associated with the ailments he suffered from.