Aaron Parecki

@oscargodson You still own the *copyright* to your contributions, even if you agree to license them to the original project.

Effectively this means the project can't change their license without getting all past contributors to agree to the new license, since it means the project has many copyright owners. Some CLAs say that the contributor grants the project owner the copyright as well, so they can still make decisions on their own.

On the more practical side, many acquiring companies will see an OSS project that has no CLA and many copyright holders as a liability since it means more ways things can go wrong, so startups will often use a CLA from the beginning.

Ultimately though this stuff is not very well tested in court so really it's just people trying to preemptively solve problems.