Rolf Sack has published a paper titled Negative Feststellungsklagen und Torpedos ("Negative Declaratory Judgment Actions and Torpedos") in the September 2018 issue of GRUR (pp. 893-97). Here is the abstract (my translation):
If the illegality of an act is in dispute, negative declaratory judgment actions justify the applicability of article 7(2) of the Brussels I (recast) Regulation. This encourages so-called torpedo actions, if one assumes, with the CJEU and the dominant opinion in Germany, that negative declaratory judgment actions as a rule block subsequent actions for damages, injunction, removal, etc. The following exposition wishes to show, that this is a mistaken development, which rests on an incorrect interpretation of article 29.
For readers who are unfamiliar with the topic, the following background from my book Comparative Patent Remedies (pp. 253-55) may be helpful. Brussels I article 27
states that “[w]here proceedings involving the same cause of action and between the same parties are brought in the courts of different Member States, any court other than the court first seised shall of its own motion stay its proceedings until such time as the jurisdiction of the court first seised is established,” and that “[w]here the jurisdiction of the court first seised is established, any court other than the court first seised shall decline jurisdiction in favour of that court.” . . . In 1995, Mario Franzosi articulated the argument that these provisions could enable a person who believed he was about to be sued for patent infringement in State X to stay any such action by first filing (in State Y) an action for a declaratory judgment of noninfringement of the State X patent. . . . The strategy might seem particularly advantageous to a potential infringer if it filed its declaratory judgment action in a country that was reputed to be quite slow in resolving disputes (such as Belgium or Italy), so as to preemptively stay proceedings in a faster forum in which the patentee likely would file its infringement action (such as Germany or the Netherlands). Franzosi referred to the preemptive declaratory judgment action as a “torpedo,” and the name has stuck. . . .
Efforts to find gaps in Franzosi’s legal analysis, or to find ways around the strategy, soon followed. Some possible approaches proved unsuccessful. In its 2003 judgment in Erich Gasser GmbH v. MISAL SrL, for example, the CJEU ruled that the second-seised court must suspend its proceedings even when it believes the first-seised court lacks jurisdiction, or is excessively slow; similarly, in Turner v. Grovit, the CJEU disapproved of the use of anti-suit injunctions that would interfere with the working of another European court. . . . Other approaches that proved more convincing—at least to some courts in Italy, Belgium, and elsewhere—were that an action for infringement and an action for a declaratory judgment of noninfringement do not involve the “same cause of action” for purposes of Brussels article 27; that article 5(3) does not apply where the declaratory judgment plaintiff is arguing, in effect, that it has not committed a tort; and that (at least some) torpedo actions are abusive and hence should not be given effect in the second-seised court.
If I understand correctly, Professor Sack agrees with the objection that the negative declaratory judgment action and the affirmative claim for infringement do not involve the same cause of action, though his argument is based primarily on the German text of article 29 of the Regulation, which uses the term "desselben Anspruchs" ("the same claim"). Professor Sack argues that, even if the English and French texts of the article can be understood as permitting an interpretation under which a negative declaratory judgment action and a positive claim for infringement involve "the same claim," under a correct understanding of the German term "Anspruch" the two do not involve the same claim. If the English and French terms are ambiguous, and the German term clear, the interest in uniformity throughout the E.U. requires that the Regulation should be interpreted in the more restrictive (German) fashion.