Porn star

Now I have just got off the phone with friend Nige, after an hour rant about the state of today's society.( we are like two grumpy old men).
Both of us hate those "baby on board" signs some parents insist of placing into the rear window of their cars. The implication of the sign is to me implicit, as it states that we as other road users should take more care when driving near this notice as if their baby's presence is more important to any other human being, located inside a motor car........anyhow this sign is not my "beef of the day"
When I was in Liverpool the other day, I noticed a young women driving in front of me. She had three young children in the back seat ( all in their child seats) and looked fairly well heeled. There was a sign in the rear of her car, and I assumed that it was the obligatory "baby" sign , but no, I was wrong, to my disbelief the bloody sign read "Porn star on board"..........
What's that all about?...am I alone in thinking that the sign was totally inappropriate to have when you have small children? What possible message does it give them?
In this dreadful age where teachers cannot tell their pupils off without risking disciplinary action and the wrath of new parents who don't want little Jack or Harriet feeling "bruised". can parents like this woman get away with this cavalier attitude to the sex industry............and can quite easily subject their kids to inappropriate messages such as the one I saw....what sort of a mother does this?
hummmm am I missing something?