Now, several Supreme Court decisions offer some help to those being trolled. First, in decisions issued in April (here and here), the Court made it somewhat easier for a defendant to recover its legal costs if the judge sees the plaintiff’s suit as frivolous. Then in June, the Court made it easier to challenge the validity of a vague patent.

Finally, and most importantly, in Alice Corp. v CLS Bank, also decided in June, the Court made it clear that you can’t get a patent just for implementing an existing business method on a computer. Alice Corporation is a patent troll established by Ian Shepherd, a former manager at the McKinsey consulting firm in Australia. In 1999, Shepherd received a patent on the general idea of handling escrow accounts on a computer.

Shepherd’s patent claimed the general idea of communicating these documents over a computer system. But the Supreme Court, following a string of decisions going back to 1972, ruled that the simple notion of “doing it on a computer” was an abstract idea that was not patentable.

The effect of this decision was quickly evident. First, the Patent Office tightened the spigot on issuing business method patents. Last month, they issued fewer than half the number that they had issued during months prior to Alice.

Patents Issued Each Month by Type

Data: U.S. Patent and Trademark Office

Second, since Alice, courts have tossed out 15 business method patents for being not patentable. These invalidations are particularly important because they show that firms accused of infringing business method patents will often be able to get the suit dismissed before costly legal discovery.

According to Stanford law professor Mark Lemley, this ability to dismiss a suit—along with the greater risk that a troll might have to pay legal costs—have curbed trolls using the “nuisance value” business model. Defendants are also not as willing to settle a patent troll lawsuit, now that the costs might not be so stacked against them—rendering the nuisance business model less profitable. Lemley sees this change contributing to a decline in patent lawsuit filings this quarter:

Patent Lawsuits Filed Per Quarter

Data: Unified Patents​

While the number of lawsuits has been declining since spring of last year, the drop has been especially noticeable since Alice (the third quarter of 2014). Of course, other factors are likely contributing to this decline in litigation. Some experts cite the importance of new procedures for challenging patents at the Patent Office as a way to reduce the cost of litigation. Others cite the stalemate in the smartphone patent wars between Apple and other companies. Most patent lawsuits today, however, are not filed by operating companies, so the drop in litigation after Alice suggests that at least some trolls are hurting.