"Captain America: Civil War" is already rife with rumors, some confirmed and some still floating in the blogosphere. One of the recent speculations comes from MoviePilot, surmising that the Hulk could be the main cause of the war between the superheroes. 

Fans have been puzzling over the civil war plot of the third installment in the "Captain America" franchise and how it would play out. So far, it's believed that Steve Rogers (Chris Evans) would clash with Tony Stark (Robert Downey Jr.) as they have opposing views toward the Superhero Registration Act. In the comic book source material, the iron-clad superhero would agree to the law, while the Cap would be against it. The focus switches between members of the Avengers, X-Men, and others. 

However, in the Marvel Cinematic Universe, none of the heroes so far introduced has a secret identity, deflating the impact of this plotline. It's been confirmed that Black Panther (Chadwick Boseman) will be making an appearance and Spider-Man will be making a cameo as well, but it isn't likely that the whole team of Avengers would fight a war over the privacy of just two people. 

MoviePilot's speculation is that the Hulk (Mark Ruffalo) would be manipulated during the events of "Avengers: Age of Ultron" and would become an uncontrollable threat to the group. This would plant the seed for the actual conflict that would occur in "Captain America: Civil War." Stark, after the devastation caused by Ultron, would go so far as to suggest firing the Hulk into space. Rogers wouldn't agree. This would then spark the conflict. 

The website further speculates that the movie may end with Captain America's death and Tony Stark's retirement as Iron Man. This would then lead to the events of the upcoming "Black Panther" movie and begin the thread for the Sony/Marvel "Spider-Man" film. 

"Captain America: Civil War" will hit theaters on May 6, 2016. It's still a long way away, and more details would most likely come to light when "Avengers: Age of Ultron" rolls out on May 1.