question about asterisks

Why is it that in posts that would have normally a phrase like: “push their agenda” I see it as “pu***heir agenda”? I could see it if one of the words was the “S” word for human solid waste and one wanted to protect those who wish to not see such language, but in a case like this? Doesn’t make sense. And I’ve seen it in different forums and from different posters so it’s not a matter of how a particular poset or forums works. Is this something the people who run the forums here do?

I have often wondered the same thing.