1. A method of classifying web content, implemented on one or more computer processors, the method comprising: using at least one of the processors, determining a first property associated with content of a web page, the first property comprising static content associated with the web page; using at least one of the processors, determining a second property associated with the content of the web page based at least in part on active content associated with the web page; using at least one of the processors, evaluating a logical expression relating the first property and the second property, at least in part by evaluating whether a constant value matches at least a portion of the content of the web page; using at least one of the processors, associating the web page with a category based on a result of the evaluation; and determining whether to allow network access to the web page based on the category.