As has been mentioned before, each feed is "run" by a volunteer. Volunteers use their own computer and their own scanner to provide a service to us, which I'm sure we all appreciate. It's not always possible to keep feeds up all the time, and I've learned it can be a challenge, especially when you only have one scanner and one computer. It's good to be understanding of all this when we question why a feed is down.
While I can't always keep my feed up, and while I miss listening to my favorite feeds when they happen to be down, I also understand the sacrafice that comes with keeping these feeds running.
I hope we can all be understanding of this and be appreciative.