Want know how to fight the plague that is patent trolls? Then you could try taking a leaf out of Rackspace’s book.

The cloud infrastructure provider, buoyed by its success in seeing off a patent infringement lawsuit over Linux just last week, has now come out with all guns blazing, launching a counter-attack against the very same troll that failed to stitch it up.

Rackspace has just filed its own lawsuit against two companies: Parallel Iron and IP Nav, which likes to call itself a “full service patent monetization firm”, but is in fact, “the most notorious patent troll in the US” according to Rackspace’s lawyers.

Rackspace’s general counsel Alan Schoenbaum describes the case in its blog, relating how it was originally sued by Parallel Iron along with eleven other defendants for allegedly infringing on three patents that relate to the Hadoop open-source distributed file system. The case actually dates back to 2010, when IP Nav accused Rackspace of patent infringement on behalf of Parallel Iron. At the time, IP Nav refused to reveal any details about the accusation, instead asking Rackspace to sign a forbearance agreement that would require either party to give the other 30 days’ notice before suing the other.

Rackspace says that it agreed to this, only for Parallel Iron to immediately break the agreement by filing an unannounced lawsuit against it when it realized it wasn’t going to be able to hold anyone hostage. As a result, Rackspace is now taking action against the trolls for breaking this forbearance agreement. It’s asking for damages to be awarded for breach of contract, and has also asked the judge to dismiss any patent claims surrounding Hadoop.

The lawsuit follows hot on the heels of Rackspace’s legal victory last week when it saw off another patent claim from Uniloc, which had tried to enforce a patent on a mathematical formula used by Linux.

Following this episode, Schoenbaum announced that Rackspace isn’t going to take it anymore. The company claims its legal bills have risen by more than 500% over the last three years due to patent trolls, and this new action against IP Nav and Parallel Iron is all about trying to get the trolls off their back.

“Patent trolls like IP Nav are a serious threat to business and to innovation, writes Schoenbaum.

“Patent trolls brazenly use questionable tactics to force settlements from legitimate businesses that are merely using computers and software as they are intended. These defendants, including most of America’s most innovative companies, are not copying patents or stealing from the patent holders. They often have no knowledge of these patents until they are served with a lawsuit. This is unjust.”

“Our goal with this lawsuit is to highlight the tactics that IP Nav uses to divert hard-earned profits and precious capital from American businesses. This time, the patent troll should pay us.”

Rackspace’s full complaint against IP Nav and Parallel Iron can be read here.