On a train coming out of London around 16:00, so fairly busy but not too bad, two friends sitting across the aisle from me were talking. One said "I kept my "Baby on Board" badge, so if I was travelling any later I can wear it to get a seat."
I have to admit, it had crossed my mind previously that this could happen, but I hoped women would be responsible enough not to risk spoiling it for others by abusing the badge. Should the badge have a simple date on them? For example, if the badge had the year of issue it could be seen to be "valid" up to September the following year.