Clay Shirky:

we are not driving a car, with gas, brakes, reverse and a lot of choice as to route. We are steering a kayak, pushed rapidily and monotonically down a route determined by the enviroment. We have a (very small) degree of control over our course in this particular stretch of river, and that control does not extend to being able to reverse, stop, or even significantly alter the direction we’re moving in.

quoted by Cory Doctorow, who continues:

…could just as readily apply to changes in copyright, lossily compressed music, or spam: they are characteristics inherent in the ecology itself. The discussion needs to center around how to exist in their presence, not how to change them.

Update: Clay adds this:

The Web, meanwhile, is chaos. Chaos! You can link anything to anything else! Dewey would plotz if he saw such a tuml. How on earth can you organize the Web? It plainly isn’t now, and it never can be.