This is a tricky issue. First off, news organizations have always had rules for ads they would not accept, some based on good taste, some based on extreme political stances of either side. Mainstream newspapers tended not to accept ads from extremists groups.
Publications with a point of view (such as the publication cited in this thread) might not be so open minded.
Also, while generally news media are pretty flexible about printing ads with questionable honesty--it's not for them to judge ad claims--in extreme cases of blatant fraud or propaganda they won't run an ad.
Needless to say, a private news organization should have the freedom to decide for itself what ads to run and not to run.
In my own opinion, I don't think communications carriers should be venturing in certain lines of businesses where they could be excused of conflicts of interest. IMHO, AT&T should not have purchased AppNexus in the first place. But those days are gone.