They are quite common in most forms of art seems to be the best answer for your question :)
Depending on weather or not you like it or hate it say Being in ensemble is an instresting/malicious time because.....
I believe because it was for the Christian persecution that took place around A.D. 64, since a lot of Christians did not want to give up their faith, but did not want to be killed, they hid every Christian symbol (I guess this could be the right answer, hope I could help!)
It can be used to create many different types of art that we weren't able to in the past. It'll also be used to interact with many different people in the world. I don't know if this is the answer you're looking for though.
