The war on (some) trolls continues unabated. This week, author and activist Cory Doctorow spotted a subtle rule change that could make patent trolls' lives really difficult.

The Judicial Conference of the United States decided to sunset a procedure left over from 1938 that trolls has been using to issue blanket patent infringement claims. Under Rule 84, a set of standard forms was available to smaller applicants to streamline their access to justice. But the forms had not been kept up to date and had largely fallen into disuse -- apart from Form 18.

Using this form, patent trolls can attack their victims without having to explain why they think the patent has been infringed. A similarly weak charge in any other lawsuit could be brushed aside early in the process. By using the approved, simple form, the attacker can ensure its victims are unable to successfully stem the attack in an inexpensive "motion to dismiss."

Immunized against early challenge, the troll is very likely to succeed in blackmailing every victim into submission, regardless of the merits of their claim -- usually few. Once the lawsuit is started, the costs quickly escalate, which is why most victims simply pay up when attacked and avoid going to court. The risk of a ruinous lawsuit is too great for all but the well-funded.

Of course, this changes little for the big trolls, who can afford to be more expansive in their attacks and don't need to hide behind antique court forms. But smaller trolls funded by their successes in court will likely find their income drying up because of an inability to shake down innocent victims. Together with earlier problems caused by the Supreme Court's Alice Corporation vs CLS Bank decision and by adjustments to the rules and procedures introduced in Congress, it's no wonder some troll masters are starting to see the writing on the wall.