as far as i know...and from what i heard from miller's talk which was recorded at the icmc recently....the pd licence is really very open...and you can do whatever you want with it nearly.
so what i'm guessing is that it would be up to you to take any steps towards 'owning' or copyrighting your own work.
but really...i find it very hard to believe that anyone would ever try to steal your patches. what would they have to gain? who's going to pay money for patches that run in a system that is otherwise completely open source?
university students....some of them are so full of conspiracy theories....take what they say with a grain of salt i reckon.