Sadly we live a very real world where software patents do exist. However, with software patents, when do you stop patenting your own idea, and start patenting others?
You can only have so many applicable ideas that you can put into a virtual system. Even if you start stealing other peoples ideas and patent those, you will still run out. With physical patents, you can always expand, but not with virtual concepts. Eventually, someone will have patented every idea possible that can be put into a virtual space, and you will have to pay for everything. Which is ironic because much of what you will have to pay for might of been your idea, but a piece of paper somewhere says your idea belongs to someone else.
Someone here recently mentioned "The tragedy of the commons", that fits pretty well here.