As various draft versions have been leaked, the language has been watered down significantly, but major problems still remain.
Arguably, none of the text is more troubling than what amounts to a mandate for copyright holders to have the right to veto any new technology which could be used for infringement:
In order to provide the adequate legal protection and effective legal remedies
referred to in paragraph 5, each Party shall provide protection at least against:
(b) the manufacture, importation, or distribution of a device or product, including computer programs, or provision of a service that:
is primarily designed or produced for the purpose of circumventing an effective technological measure; or
has only a limited commercially significant purpose other than circumventing an effective technological measure.
Any technology capable of copying or distributing works will be used by someone to do so illegally. In most cases, the commercial uses of new technology doesn't exist until well after it becomes available.
Imagine a world where the printing press, radio, television, the photocopier, audio cassettes, the Internet, CD burners, file lockers, and encryption could all have been suppressed on the grounds someone, somewhere would use them for illegal purposes. That is exactly what ACTA would allow.
It fails to take into account that the same technologies used for copyright infringement are essential to everything from modern medical advancements to national defense.
There are still several hurdles to clear before ACTA can officially go into effect. First, at least six countries whose representatives signed the agreement must complete any internal ratification process.
US officials have chosen to bypass ratification by signing it as an executive agreement. This is guaranteed to result in legal challenges based on the president's lack of authority over intellectual property law under the US Constitution.
The European Union, which sent a representative to participate in Saturday's ceremony but hasn't signed the treaty, will also be instrumental in the process. Without their participation, the ACTA coalition could fall apart.