I have first hand experience with the anti-poaching policy, since I work for a different company that employs the same practice.
When I was searching for a job within town I was told by recruiting firms and other companies that they could not and would not talk to me, because of the agreements they have with my employer.
It makes searching for a job extremely difficult as one might suspect. It is effectively a job monopoly, since wages become fixed due to the lack of competition for jobs.
For the longer term, I would like to see a federal law enacted against the anti-poaching employment practice.