I'm sure that if we try we can come up with a whole crapload of jobs they shouldn't do that "make sense".
What makes you think that, non-registered sex offenders, or never caught/convicted sex offenders aren't already there?
Why not just make a law to prevent every single possible thing that could concievable cause harm to anyone? Because it's STUPID, that's why. So is this. If you want to control everything they do for the rest of their lives, imprison them.
"imprison them", that's what it always comes down to, and because they're not in jail we end up writing laws like these.