The New York Times runs an editorial on the MGM v. Grokster decision that gets to the heart of why EFF took the case on behalf of Grokster co-defendant StreamCast Networks:
It is impossible to strike down software like Grokster for its use in illegal file-sharing without also destroying its capacity for legal and socially beneficial activities.... Freedom of information is at the root of American democracy, and yet every day we see that freedom being compromised, controlled and limited. The Grokster decision is a ruling in favor of keeping our bets open about which technologies will turn out to serve our freedoms best.