We should get together a small group of people who know what they are doing to think about what such an amendment should say.
Just to spitball a bit:
"The transmission of any data owned by one person to another shall not be infringed by the government of the United States."
Something like this is what we should have had in 1995. Instead, all the corporate players are now in the place -- it'll be a long, hard fight. Whoever puts something like this forward should be prepared to be ignored, at least until they can't ignore you any longer. Then they had better be prepared to be slimed. There will be all kinds of over-the-top attacks: child pornography, terrorists, etc. Supporters had better have a strong argument (and supporting sob stories) in place for when that day arrives.
The counterarguments can be simpler than you think;
Senator, would you prefer ineffectively blocking child pornography that paedophiles can work around or allowing children the chance to innovate and communicate freely for their future?
Senator, would you prefer ineffectively blocking occasional terrorism that will piss off terrorists or allowing political discussions freely?
Senator, would you prefer blocking piracy or allowing anyone to share their content freely? DMCA cracks down on this; a catch-22 that the creator must sell it to claim damages against DMCA notice abusers unless the police charge them with perjury. Not to mention that the notice is scary not only to creator but to other people wishing to re-share. The DMCA does not discriminate against non-commercial sharing.
Here's a good history of anti-Internet measures by USA: http://www.rense.com/general85/net.htm
Here's Australia's version: http://libertus.net/moreinfo.html
I liked this thread so much I wrote a blog entry on it. I think it's something we should start talking about a lot more seriously. The time is getting very late. http://news.ycombinator.com/item?id=3464227
They're claiming that the sender doesn't own the data being sent.