US trade group the (Entertainment Software Association) have announced a against the Chicago Transit Authority this week, over a new ban on ads featuring Mature and Adults-Only video games.

ESA chief Mike Gallagher believes the ban is unconstitutional, and goes against the First Amendment which sees games protected in the same way as other forms of entertainment.

The lawsuit might not produce the desired effect however, indeed, there seems to be a risk that Chicago will instead also ban other classifications, in order to make things 'fair'.

Take-Two have already taken on Chicago in the courts after adverts for IV were pulled by the Transport Authority.

More on this at Joystiq.

By Luke Guttridge