TV auditions- why can't we audition?

hiya, Starz again. Do you find it annoying when your fav TV show is starting a new series and they need some people to play some parts for them. Imagine you want to play one of those parts, but you don't have an agent and you dont know where it is for auditions- I think the tv programs should give this info out on the websites for people who want to be on the show can find out where to audition.xx Starz