put your code into the public domain. if you really wrote it yourself (you are no pirate) that completely prevents piracy.

any other licensing strategy creates a pirate once someone copies some of your programs. and you did not ask for copy protection.

even using the GPL is no real protection, you need organizations like gpl-violations.org to track down the pirate companies. but you are the Good Guy in this case.

Check out third-party licensing technologies that allow you to strike a good
balance between controlling piracy and supporting casual sharing/viral
marketing. My company uses SoftAnchor from Uniloc. Works pretty well, I'm
told. Uniloc allows you to use the piracy data, graphically defined by
region (country, continent, etc.) and throttle the licensing parameters to
adjust for areas of aggressive piracy. This also allows the loosening of
licensing restrictions in areas of lower piracy to promote viral product
marketing and greater sales.