use your energy to write your own code. It's far less trouble than the needed to have some help from laws created to protect proprietary software.
Oh please, copyright law doesn't protect non-free software more then it protects free software, just take a look at the GNU General Public License. Non-free software comes from the mentallity of a few people that consider it their "goal" to deprive people of their rights. It doesn't come from any law; infact the law helps us with keeping our software free. It is a wonderfull double edged sword.