ACTA would make service providers copyright police
After nearly two years of excuses for the secrecy of negotiations over ACTA, the Anti Counterfeiting Trade Agreement, a full draft of the proposed treaty has been leaked online and it looks just as bad as critics have suggested.
Among the worst provisions of the proposal is the requirement that third party service providers must implement measures to proactively identify and elminate access to content that's in violation of copyright law.
Failure to do so would make them liable for such infringement. Even worse, according to a note from New Zealand's negotiators this would even include search engines.
Assuming some service finds a way to implement this sort of proactive system, their ability to safeguard the privacy of users would be severely diminished.
Under current laws, when content owners identify content they believe infringes on their copyrights they can notify the service provider, such as YouTube, and demand that the content be removed. This is known as notice and takedown.
Under the ACTA proposal content owners would also be entitled to any information the service provider has which could identify the user responsible for the content without any judicial oversight.