This is superb reporting by NPR (link at bottom) on the murky business of software patents and how the real spirit of patent and copyright laws have been subverted by patent mills out to make a quick pile of cash.
These days greedy companies get patent protection for the most ridiculous and obscure algorithms. Most developers behind these patents don't even know what the patents actually cover. The patents are then sold to patent mills, which are front companies with a few lawyers and accountants collecting patents.
The patent trolls then go after anyone they deem to be a good target to extort money from, using frivolous lawsuits. From the thousands of patents in their lists, they can cash out with one or two, and that's what keeps this repugnant but lucrative practice alive.
The fact is that just about any idea anyone can fathom is covered in one way or another under one or more patents, mainly in vague general terms. That is why software is under siege now. Any entrepreneur who would dare conceive and implement a new product with a modicum of success, will inevitably be in the cross-hairs of patent lawyers.
And so we give yet another boost to countries like India and China and extinguish innovation in USA. I'd like to see how far these sleazy patent sharks can get in those countries.