Part of the DMCA.
Often referred to as OCILLA, this act creates a safe zone for online service providers, including Internet Service Providers, against copyright prosecution if they adhere to guidelines and take actions to block against potential pirated materials on their network if they receive notice of infringement from companies involved proving they have been providing an outlet for copyright infringement. This act also provides a safe zone from the ISP's users should the material in question prove to be legitimate. The act would then relinquish liability from the ISP should the user decide to file complaints or lawsuits. OSCILLA also provides subpoenas for private information about their users.
