Github ToS and Open Source

[Ralf Mardorf]

An issue could be, if somebody does use license X for her code and
assuming license X demands that a fork needs to continue using the same
license X, somebody forking this code under this license could not add
an additional license to the code. If license X + Y were used in the
first place it's another situation, than forking code published under
license X and adding license Y. This could offend license X.