Aspects relate to categorizing requests for online resources as originating from spiders or not. Such resources are associated with respective contacts, and if a non-spider requests a resource, then a contact associated with that resource can be notified. One example method for determining whether to notify a user associated with a network resource includes identifying, via a processor, an entity making a request for a resource associated with a network address, wherein the entity has extracted the network address from a machine-readable code. The method then includes serving the resource to the entity in response to the request. The method then includes determining if request is not abusive, and only if the request is not abusive sending a notification to a user associated with the resource that the resource has been accessed.