Patent trolling has become so widespread that no business is safe. A couple of months ago I noted that Whataburger, Kroger and J. Crew had joined the anti-troll fight. Now one patent troll has attracted an even more formidable foe: Martha Stewart.

GigaOm reports that Stewart's firm, Martha Stewart Living Omnimedia, has filed a lawsuit against LodSys, one of the nation's most prolific patent trolls. LodSys claims to own concepts related to in-app updating, and it has threatened numerous app developers for infringing its broad patents.

In July, Lodsys sent Stewart's media empire letters warning her that four of its iPad apps infringed LodSys's patent. Lodsys demanded $5,000 for each of the four apps to license the patents.

Instead of paying up, Stewart went on the offensive. Her firm filed suit in a Wisconsin court seeking a declaration that it hadn't infringed four of LodSys's patents, and that those patents were invalid.

That could be bad news for the patent-trolling firm. The trolling business model depends on asking for sums small enough that it's not economically rational for the defendant to fight in court. The legal fees required to fight a patent infringement lawsuit are vastly more than $5000, so a rational firm will just write a check to make the troll go away.

But evidently, Stewart has decided to fight LodSys's demands anyway. That will drive up LodSys's cost of doing business. And if she succeeds in invalidating LodSys's broad patents, it could save lots of future app developers from LodSys's demands.

This also is an example of a case where a faster method of invalidating patents could be helpful to defendants like Stewart. A judge may eventually rule that LodSys's patents are invalid, but getting there is likely to take years of litigation and hundreds of thousands of dollars in legal fees. An expedited process for challenging dubious patents, like the one advocated by some technology companies, could reach the same result more quickly.