1. A computer-implemented security method comprising: receiving, at a computer server subsystem and from a web server system, computer code to be served in response to a request from a computing client over the internet; modifying the computer code to obscure operational design of the web server system that could be determined from the computer code; supplementing the computer code with instrumentation code that is programmed to execute on the computing client; and serving the modified and supplemented computer code to the computing client.