If you've got a brilliant idea and want to start a business, beware the patent trolls.
That's increasingly what start-up companies and entrepreneurs are being told, as trolling—when companies buy up tons of cheap patents and profit from them by threatening infringement suits against others, in the hope of settling—has become a predatory activity that costs the U.S. economy $80 billion a year, according to one oft-cited study from Boston University.
Though some may dispute those numbers, nearly everyone agrees that abusive patent trolls are a problem that has ballooned in recent years, particularly in the software industry. All three branches of the federal government are now trying to rein them in.
Here's what you need to know about patents and the trolls that eat them—and why Washington is having such a hard time turning them into stone.