If you were to host it on your home computer, there would be two problems.
There would be some major buffering problems, major.
Also, it would only be able to support most likely a maximum of 10 users at a time.
There are no free SHOUTcast servers, they consume massive amount of bandwidth. Also, keep in mind that ISP's don't allow public servers on a home connection. The chance of them catching you are slim, however if they do your in trouble.