The Chofetz Chaim (3:6, Be’er Maim Chaim 7) lists two basic definitions of lashon hara (gossip):
1) Saying something negative about another, even if it will not lead to any damage to the person spoken about.
2) Saying something about another which could lead to physical or monetary damage, or to embarrassment.
Even if it is not so common, baruch Hashem, nowadays, to find someone speaking lashon hara because he hates another, it is unfortunately quite common that people make jokes about others, maybe even including themselves in the joke. This is still a transgression of lashon hara, since the words spoken about another were negative. (Chofetz Chaim 1:9, 3:3) Despite the fact the two people might remain friends and no hatred is caused by the negative speech, it is still forbidden to speak negatively about another Jew, since the prohibition is in and of itself to deride another regardless of the consequences. (The Az Nidberu (14:63) discusses whether speaking lashon hara in a joking fashion is the Torah prohibition or the Rabbinically prohibited “avak lashon hara.”)
Newspapers certainly contain much lashon hara, and as the Chofetz Chaim makes clear, the prohibition includes not writing negatively about other individuals, groups or communities. Az Nidberu (14:64) discusses the issue of liability – is it the journalist who has transgressed lashon hara or the publisher/vendor?
His conclusion is that the writer is certainly guilty, for even though at the time of writing he did not tell anyone his lashon hara, once his words are published he has transgressed retroactively. On the other hand, the publisher or vendor is by and large not liable since he has no intention to spread lashon hara – he merely earns his livelihood by selling newspapers, but does not specifically intend to damage others. Nevertheless, he recommends that one should stay as far away from such newspapers as possible.