Marvel is teaming up with one of the biggest arms manufacturers in the world and fans are upset about it

On Friday morning, Marvel made a huge announcement on Twitter, and fans are not happy. 

Marvel Entertainment is joining forces with Northrop Grumman, an American global aerospace and defense technology company, and the world's fifth-largest defense contractor. We don't know much yet, but it looks like there will be a promotional comic featuring the Avengers and "Northrop Grumman Elite Nexus," or N.G.E.N. 

The arms manufacturer generates over 20 billion dollars in revenue a year. Marvel Entertainment didn't reveal anything more about the partnership, and to learn more the company encouraged fans to head to their New York Comic Con booth on Saturday afternoon. 

This partnership comes as a surprise to Marvel fans, especially just days following the mass shooting in Las Vegas. For sensitivity reasons, Marvel pulled its NYCC panel for "The Punisher," and canceled screenings of the first two episodes. Tony Stark/Iron Man, one of Marvel's most popular characters, stops selling weapons (his family's long-time business) because he realizes he's not saving lives, he's destroying them. 

Maans are not pleased with the surprising announcement, and some took to Twitter to express their opinions on the matter:

The details of the partnership are unknown, but more should be revealed on Saturday at NYCC.