Are you serious? This is entirely enforceable without unreasonable difficulty. It's easy to find out who owns an IP address and there's always contact info attached to that record. If the fine isn't paid or isn't paid on time, it's only a simple matter of shutting the company's site down 'til the fine is paid. We're not talkin' about individuals here, but companies, especially hosting services, etc. Notification would come through an official gov't somebody, not something like a spamish-lookin-email. Anybody who's setting up servers that falls for a spamish-looking-email about this, deserves whatever problems they get as a result of believing such an email. They really should know better.
And while they're at it, they should fine everyone who's DB is stolen due to stupid insecure setups... SQL injections, plaintext passwords, etc. This stuff isn't excusable, and it's pretty shocking that it's still common in late 2013. Can you imagine how much money the gov't would've made off Adobe and SONY over the past few years? That'd probably help lower our taxes (in theory).