Why do asterisks replace some words in word chums messages?

Yes innocent words are blanked out. Ridiculous when you can use the words in the game

You can sometimes get around it by spelling the word on two lines, but since pic is also banned, it's best to just say photo or painting. Stupid. Word Chums needs to get rid of this bad software.

Good question, that happened to me this week, I was chatting to my WC partner and when I put in the word PICTURE but just came up as *******, my poor partner thought I was swearing