To clarify: the linked post is bout the DMCA safe harbor rules about takedown notices. This really isn't the bad part of the law. It can be argued that the takedowns are too easy to do and that they are honored too quickly by site administrators, that they are susceptible to automation and false positives, etc... But really that's not a huge deal.

Where the DMCA is widely reviled is in its other parts, most particularly the anti-circumvention provisions that, when the law was drafted, made things like security research or reflashing a consumer device criminal acts (c.f. the Skylarov case). It should be noted that this nonsense, while it's still in the law, has been significantly dilluted by a bunch of regulatory exemptions enacted by the executive branch.