If you had complaints about the marketing for Justice League in the US and European markets, it's time to recalibrate your standards for grievance. Because whatever was done to promote Justice League in the Western world, it's nothing compared to how the movie is apparently being promoted in China:
UPDATE: Yep, that's an actual Justice League Poster being displayed in Chinese movie theaters. It was created by a fan (not by Warner Bros.) but has nonetheless made its way into theatrical displays (see HERE).
The poster takes the standard one-sheet photo of the DC superhero team and adds in the grisly photoshop details of the the Justice League heroes having murdered and/or dismembered several key figures from Fox's X-Men movie franchise, as well as members of Marvel's Avengers. It appeared in several Chinese theaters and on video hosting site iQiyi as the ticketing app for Wanda Cinema, China's biggest theatrical chain.
If Wolverine and Deadpool being impaled on Wonder Woman and Aquaman's weapons (respectively) don't do it for you, maybe seeing Iron Man's dismembered limbs or Thor's head in Batman's hand will get your pulse going? Not to be left out, Superman's hand is still slathered in the photoshopped blood of the franchise heroes he's murdered.
Needless to say: This is a super aggressive and provocative marketing approach, whose legality is questionable (using characters from other franchises). There's no real question about good taste though, because it has none; this is like every superhero movie flame-war from the Internet given visual validation. Marketing in overseas markets is a much different game than the one we know - as is their apparent understanding of what DC superheroes (keyword) are all about. There's a Zack Snyder Man of Steel / Batman v Superman joke in there somewhere, for anyone willing to tell it...
Since being spotted by fans, these Justice League murder posters have reportedly started being pulled down. Warner Bros. and DC Films have not yet issued a statement on the matter.
Justice League is now in theaters; Aquaman arrives on December 21, 2018; Shazam on April 5, 2019; Wonder Woman 2 on November 1st, 2019; Cyborg on April 3, 2020; and Green Lantern Corps on July 24, 2020.