The Surgeon General Has Determined That Cigarette Smoking May Be Dangerous
to Your Health.
I think it was between ten and fifteen years ago that it changed
to:
The Surgeon General Has Determined That Cigarette Smoking Is Dangerous to
Your Health.
More recently, the warning has branched into several more specific
warnings, about carbon monoxide, birth defects, emphysema, etc. The one
that really bugs me is the one about pregnancy, because it employs
non-parallel grammatical construction and is thus jarring. Fortunately,
since I don't smoke, I don't read it very often.
Eva