Maybe they're running the untrusted user-submitted code as processes under the 'nobody' user as a security measure. I've built something similar for my upcomin

Maybe they're running the untrusted user-submitted code as processes under the 'nobody' user as a security measure. I've built something similar for my upcoming programmer-testing service at http://codeboff.in http://codeboff.in and this is one of the precautions I've taken in my own sandboxing arrangement.