Q. If gov't is accountable to the press, then to whom is the press accountable?
A1 In a capitalistic society, the press is accountable to the almighty dollar and all of its various implications.
A2 If the press (and I guess you mean to include all news gathering & disseminating individuals and organizations) fall afoul of the law, such as libel, then they are accountable to the legal system.
A3 In the end, I suppose everything is accountable to the will of the people, but this usually means pitchforks and pyres.