Stealing planning documents is another thing but I am quite surprised that it's okay to leave your company and work for the competition two days later.
What a lot of companies attempt to do is put in anti-compete clauses in to the civil employment contract.
They are often unenforceable or if they are they are heavily time limited unless a large financial incentive is provided to balance the loss of earnings.
If your contract only says "Not allowed to work in the field for X month after leaving" and there is no compensation, it's toilet paper.
It's called desertion and threatened with the death penalty.
BTW Freedom to work for whoever you chose is on one the rights laid down in the Universal Declaration of Human rights.
and I think its implied in the US constitution
What you're saying is true in many places in the EU. It's very sad.
Contract law is very simple in most of the EU. The most you can hope for here is non-disclosure.