How Many Virgins Hang Out Under Highway Overpasses?

This is pretty loony:

A steady stream of the faithful and the curious, many carrying flowers and candles, have flocked to an expressway underpass for a view of a yellow and white stain on a concrete wall that some believe is an image of the Virgin Mary.
[snip]
"We believe it's a miracle," said Elbia Tello, 42. "We have faith, and we can see her face."
[snip]
The stain is likely the result of salt run-off, according to the Illinois Department of Transportation. The agency does not plan to scrub it off the wall.

Ooooooookay... I wonder what would happen if someone gave these people the old Rorschach Test. I bet they'd see more virgins than at your average christian rock concert.

Also, I'll ask the same question I ask every time someone sees Jesus or satan in a taco or plate of pancakes or something: how do these people know what Mary looked like, anyway? Did she sit for a lot of paintings back in the desert in Nazareth?