Copyright is a balance between expression that the owners can control, and expression that is left open to the commons. There is a commons for intellectual property, and the Constitution is committed to feeding that commons. For the commons is a resource for other creators later on. And the commitment of the Constitution is that there be lots later on. Stanford law professor Lawrence Lessig describes well in the above paragraph the thin tightrope that must be walked when designing the rules for Copyright Law.
Intellectual property is fundamentally different than other forms of property.
Claims that intellectual property should be treated like forms of private property simply do not take into account the countervailing speech interests inherent in creative expression. Despite this need, copyright has radically changed in recent years. Deviating dramatically from its public interest roots, copyright today resembles an incomprehensible set of prohibitions structured to maintain monopoly control over creative expression. Ever-vigilant extensions in the length of protection granted to copyright have increased from 26 years maximum at its origin to what can now last for more than a century. Together with the widened scope of works considered worthy of copyright and the additional rights granted under recent legislation , the balance has already dramatically shifted away from the public commons, and the scale is in grave danger of tipping even more sharply.