P.J. Tobia chronicles the demise of a bill which would have allowed transsexuals to change their sex on their drivers license without having to offer up an invasion of privacy everytime they show ID:

But last week, the sponsors of the bill—Reps. Jeanne Richardson and Mike Kernell among them—withdrew the law change after the health committee tacked on an amendment proposed by Rep. Jason Mumpower. The amendment required that any change of sex on a birth certificate be reflected on the document, essentially creating a new category of sex. “A birth certificate can be amended with the designation MTF,” Mumpower tells Pith, “designating male to female, or FTM designating female to male.”

Mumpower says that it’s a security issue, though he doesn't say exactly how. “During one of these operations, someone’s appearance is changed…so if someone were to present a birth certificate with a changed name and an altered appearance, the fact of gender needs to be represented.”