I cringed when I saw the large, pornographic decal on the rear window of the truck in the parking lot. It wasn't just a simple silhouette of a shapely female, as commonly found on the mudflaps of big trucks, but a blatant depiction of a very private act.

As my 8-year-old daughter and I walked past the vehicle I tried to distract her before she could see it and ask the inevitable question: "Daddy, what does that picture mean?"

She didn't see the image. Whew! If she had, I would have been tempted to wait for the owner of the truck to return and let my daughter ask him that question.

What would he say?

Would he even care?

I'm not hyper-conservative when it comes to the display of nudity or human sexuality, as long as it's done in appropriate places with some level of sensitivity to the ages of those likely to see it. The television and movie rating systems were created for that very reason.

I do object to people shoving what is generally considered innappropriate material in my face. On the back of your window? Really?

I'm all for freedom of speech. I'm American. I'm a journalist! But let's show a little civility. Please.

I've often wondered about the psychology behind people decorating their car bumpers and windows with stickers and decals. Just as some people consider their vehicles status symbols, or a way of expressing who they are, I'm guessing it's the same for these little adhesive message signs.

Environmentalists paste "Save the Whales" on the back of their hybrid cars. Patriots display the U.S. flag. Hunters slap "I brake for elk" stickers on their 4x4 trucks. NRA supporters prefer "I own a gun because you don't want me to" stickers. Christians favor "Jesus Saves" decals. Fantasy lovers proclaim "My other vehicle is a unicorn!"

Many people adorn their vehicles with stickers promoting their favorite rock band, sports team or politician to communicate to others who they are or what they stand for.

What exactly are those who put pornographic images or obscene words on their vehicle trying say? "Hey! Look at me. I'm an ill-mannered, unpleasant person who hates women!"

Perhaps I should greet these people with a smile and say "Thank you so much for making it easier to determine that you're a jerk."

I used to enjoy reading bumper stickers years ago, when a majority of them included funny sayings such as "If we quit voting will they all go away?" These days, too many bumper stickers simply promote filth.

I used to put stickers on my vehicle andndash; in my teens and early 20s. Then one day I decided that I'd rather have people get a sense of who I am andndash; my interests, philosophy, religion, moral character andndash; by talking to me directly instead of going off a few bumper stickers.

First impressions andndash; and bumper stickers are exactly that andndash; can be nearly impossible to reverse or undo. Some people believe that bumper stickers say everything about a person. Think about the next time you put a sticker on your car.

As for my daughter? Well, the next time she wants me to explain a bumper sticker or decal, I hope it says something like: "Driver cleverly disguised as a responsible adult" or "You! Out of the gene pool!" or "God must love stupid people. He made so many."

Now those are bumper stickers I can live with.