A week isn't complete in the tech industry without somebody suing somebody else over patents.

This time, Facebook is countersuing Yahoo, charging that Yahoo violated 10 of its patents. This move, of course, comes less than a month after Yahoo sued Facebook for allegedly infringing on 10 of its patents.

Facebook's countersuit shouldn't surprise anybody; it was always going to fight fire with fire, especially since Yahoo started this unnecessary fight. It's the same reason Facebook purchased 750 patents from IBM last month -- it needed more ammunition in a patent arms race that is quickly escalating.

But I'm shocked by some of the patents over which these two companies are suing each other. One of Yahoo's patents focuses on the "optimum placement of advertisements on a webpage", while Facebook has two patents that cover a "system for controlled distribution of user profiles over a network." Yahoo owns the patent for a "method to determine the validity of an interaction on a network", but "generating a feed of stories personalized for members of a social network" belongs to Facebook.

You really can receive a software patent for almost anything these days, it seems.

Facebook and Yahoo aren't the only ones collecting patents and threatening to use them like stockpiled nuclear weapons, though. Here are just some of the patent disputes that have made headlines in the last two weeks: Apple and Samsung, Microsoft and Motorola, RIM and NXP, Oracle and Google, and Tivo and Motorola.

Patents have played an important role in protecting an inventor's intellectual property and fostering innovation throughout history. However, their usefulness in software is far more limited, and in recent years has simply become damaging to innovation, thanks to patent trolls using IP they've acquired to sue smaller tech companies and make a quick buck.

Patent law simply wasn't designed for the always changing, rapidly developing world of software. Inventing a way for "generating a feed of stories" isn't the same as inventing a new type of fuel injection system or a new ultralight alloy for space travel. But software companies file patents like crazy because companies like Yahoo get desperate and start suing, and your only defense is to have your own stockpile of patents that will help you negotiate a settlement faster.

It's the tech industry's version of mutually assured destruction. And all the while, the patent situation inches closer toward a crisis that will make the SOPA controversy look like a walk in the park. At some point in the future, a company is going to skip the settlement and use the courts to shut down a popular and universal feature on the Web's top domains, simply because it has a patent that says it came up with the notion first. It will be a shock that reverberates all the way to the U.S. government and the World Trade Organization.

I suspect a patent crisis is both necessary and inevitable. The reason is simple: there isn't enough political will or pressure to institute massive patent reform without a crisis to rally around.

That's why the cycle of patents, lawsuits, and settlements isn't ending anytime soon. Now, if you'll excuse me, I'm going to go file a patent for a method of identifying patent trolls, just to see if I can.