Protecting BGP routing from errors and malice is one of the next big challenges for Internet routing. Several approaches have been proposed that attempt to capture and block routing anomalies in a proactive way. In practice, the difficulty of deploying such approaches limits their usefulness. We take a different approach: we start by requiring a solution that can be easily implemented now. With this goal in mind, we consider ourselves situated at an AS, and ask the question: how can I detect erroneous or even suspicious routing behavior? We respond by developing a systematic methodology and a tool to identify such updates by utilizing existing public and local information. Specifically, we process and use the allocation records from the Regional Internet Registries (RIR), the local policy of the AS, and records used to generate filters from Internet Routing Registries (IRR). Using our approach, we can automatically detect routing leaks. Additionally, we identify some simple organizational and procedural issues that would significantly improve the usefulness of the information of the registries. Finally, we propose an initial set of rules with which an ISP can react to routing problems in a way that is systematic, and thus, could be automated.