It's not like Katherine Heigl is the last person on earth that smokes. PLEEAAASE, she's just one of those celebs that get photographed smoking on a regular basis. You probably aren't a smoker, and never were a smoker, so you clearly would have no clue how hard it is to kick the habit. It's her life, her lungs, let her pollute her body if and how she pleases, get over it.
seriously, take a good look, anyone see the resemblance?