Two of the computational idea patents Apple used to attack Samsung have been invalidated by a court.

That's a victory for software freedom, but an limited and extremely expensive one. We need to protect software from all patents on computational ideas, all at once.

These patents are often called "software patents", but that term gives the wrong idea of what such patents do. A patent is never associated with any specific code. Rather, it is a monopoly on implementing some specific, stated idea & in these cases, a computational idea. Any code which implements the patented idea, or any hardware which does, can be the basis for a lawsuit.

Another solution I've proposed is to legislate that software is exempt from patent law.

This illustrates the error of focusing on "patent trolls" and ignoring other patent aggressors. Apple is the biggest patent aggressor in the software field, and we can hardly call it a patent troll. Its products are full of proprietary software

with malicious functionalities, but they are certainly a real business.