The rule is simple; caveat emptor. Check what you are buying before you buy it.
For me, patents/copyright do not add value to society. Most people would create their inventions/artistic works without benefiting financially. In fact most people who actually do the creation never see the benefit, nowdays its a corporation that holds the IP and makes all the money, the creative individual gets a salary (and eventually fired or leaves).
The point is opensource is the way to do things. Let anyone create a new Bitcoin, if its better than the old one, we can use that.