copy the board layout program everything
The best protection from such is to add a feature every 3 months, you will always be ahead of the game. I once worked in an envirinment (microfiche) where all user 'programs' were source (no compilation) and remember once a customer made a new font for titles and, lo and behold, a few months later another customer had that new font with the very same minor mistake (a missing dot in the 'K').

I have heard from several people with some special tricks these guys can crack the code from any damn locked chip
The rule here is that for that to be feasible the (potential) sales volume must be high enough. If you are making something to be produced in tenthousands in a den of thieves forget about locking the code as your only defense, use means such as using mislabeled components (in 10.000s you can get such). In the most extreme cases you can use the Dallas secure micros that lose the memory if removed.

Erik