Assuming this follows the comic storyline Civil War, this whole thing will be over a thing called the Superhero Registration Act, which basically means that superheroes must register their secret identities with the government, and cannot take action without government orders. Iron Man is pro registration, and Captain America is anti registration. Black Panther (in the comic, at least) opens up the borders of Wakanda to any hero who doesn't want to register.
Personally, I'm with Captain America. Superheroes need to be able to respond to a threat at a moments notice, and shouldn't have to reveal their identities. Especially given how easy it is for evil organizations (HYDRA) to infiltrate government agencies.