The lawsuit (which the article has included a link to!!!) claims that Specialized's website did not disclose certain fees (eg handling fee, battery disposal fee) prior to the checkout page, in violation of laws in both Virginia (where the plaintiff lives) and California (where Specialized is headquartered).
The suit was filed in the Northern District of California federal court, because: 1) a national class-action suit can only be filed in federal court, not state court, 2) both the lead plaintiff and Specialized reside in different (ie diversity) states, and 3) that court's geographic district includes Specialized, as the defendant, and also is the presumed location where their website was designed.