Thanks for the link, Glenn. I'd forgotten about that particular use of obscenity statutes....
Here's another one, to a story about a more current prosecution under Federal obscenity statutes:
http://a.abcnews.com/TheLaw/Story?id=4222798&page=1
So, yes, Federal limitations on the First Amendment are alive and well.
And isn't there a Zen koan that goes, "What is the smell of Internet fertilizer?"