This is a very astute comparison, but the power relationships involved are so different that we may be able to treat the two situations differently. The DMCA fails in practice because the violators are millions of isolated individuals, and trying to stop them is like trying to carry water in a sieve. A comparable website privacy act would be trying to protect the individuals from the corporations, and corporations are bigger, are easier to hit, and have more to lose. So I think it's not necessarily as futile as the DMCA.