Copyright (and patents - they're different, but have similar ideas behind them) were meant to be a compromise. Creator gets to profit from their idea for a predetermined time, with protection from the state, then when that time is up, it becomes owned by "the people" and therefore nobody's use is any more legitimate than anyone else's. But Disney broke copyright by extending it to its current ridiculous extent...

So I guess what I'm saying is, as long as the period is short, it can be a net benefit - but when it's life plus 75 years or whatever it is now, it stifles creativity.