Good question. I was surfing over at Wizbang, and he asked it first, as far as I know.
I have some small expertise in this area, and I can imagine that the Division of Probation and Parole is going crazy trying to figure out where all these people went.
The deal is, a sex offender can't cross a parish line without written permission from his probation or parole officer and when I was doing sex offender work, the state parole board had adopted a no-tolerance policy for sex offenders absconding from supervision.
The Louisiana State Police registry lists all the sex offenders in Orleans Parish, and anyone can search it. Just go here and use the search engine to search Orleans Parish.
Somebody is going to be asking for a whole lot of absconder warrants.