Last time I checked it needed you to subscribe through some provider who charges money, ISPs used to offer it with the Internet access. Is it really possible to access for free?
For some reason your post reminded me of a list I saw quite recently of (surprisingly working) open/free news servers (maybe dotsrc was on it).
I can't seem to remember or find the exact list or page I saw before, but for anyone interested here are a couple of sites with a few of the other servers I remember.
Note: I haven't tested these, some may not work, some may not be deliberately open (perhaps just misconfigured), some may not allow posting, some may require registration, some may carry only a few local groups, etc etc etc.
Also, this post is related to text usage; if any of the following servers carry binary groups it's unlikely they'll have complete files.