Computer-implemented methods and systems are provided for scanning web sites and/or parsing web content, including for testing online opt-out systems and/or cookies used by online systems. In accordance with one implementation, a computer-implemented method is provided for testing an opt-out system associated with at least one advertising system that uses cookies. The method includes transmitting a first request to an opt-out system, wherein the first request corresponds to a first test for testing at least one of the opt-out system and an advertising system; receiving a first stream sent in response to the first request; determining a first outcome of the first test based on the first stream; and generating a report based on the first outcome.