Patenting ideas is also an excellent way to prevent someone else from doing what you suggest; the patent-holder merely needs to grant a royalty-free patent lice

Patenting ideas is also an excellent way to prevent someone else from doing what you suggest; the patent-holder merely needs to grant a royalty-free patent license to everyone once they have the patent. (See Sections 7 and 8 of GPLv2, for an example.)