A Shitfish™ is someone who rides coattails. Attempts to gain notoriety off the work of others. A shit fish is the lil fish who swim behind sharks eating their scraps instead of going off and finding their own food. A lazy uninspired person who aspires to benefit from the efforts of others merely by association.
That dude is such a ShitFish™ he starts fights with accomplished people publically just to get attention for his unknown website.