Before taking any action in court, it is important to first thoroughly think about your defense/protection strategy as a whole, so as to avoid a fatal backlash!
You could in fact end up biting your fingers, especially if your trademarks are not, or just hardly distinctive.
This is what happened to Sneep. This company is the owner of L'Argus, a weekly magazine that has been publishing a preference rating of second-hand vehicles since 1927, and has strongly leveraged the term ARGUS in trademarks and domain names.
Sneep detected the websites www.la-cote-argus.com, .net and.fr from Muse Media, which are used in the same sphere of activity as Sneep's. The company then filed various claims to obtain that these domain names be transferred to Sneep and also served a writ on Muse Media for infringement and unfair competition.
Muse Media counter-attacked with an action for revocation of French word marks Argus Auto, Cote Argus, L'Argus and Valeur Argus of 2007 and 2009, for lack of distinctiveness, and won.
The Paris Court of First Instance held that the said trademarks were not distinctive at the time of the filing, in view of the activities concerned (the term "Argus" actually describes the said activities), and that Sneep had not demonstrated the distinctiveness of these signs through evidence of use (undated/inaccurate proofs provided; signs not used as trademarks...).
So it appears that Sneep did not manage to build a conclusive body of evidence!
Finally, just like for concepts, the way you communicate on your trademarks is also very important. It is therefore advisable to prepare your communications very carefully before issuing them, so as to avoid shooting yourself in the foot!
In this particular case, Sneep had in fact recognised that, when associated with the term "Argus", the French terms "Auto", "Cote" or "Valeur" could not make the "Argus" term distinctive, as these are standard and descriptive terms that cannot fulfill the original functions of the products and services associated with a trademark...