It is forbidden to learn Torah on Tisha B'av [except for certain sections such as Eicha and parts of Yirmiyahu etc]. The reason is that Torah makes one happy "pikudei Hashem yesharim mesamchei lev". This would certainly not apply to newspapers. Au contraire [did I spell that right?], newspapers are quite depressing. The Mordechai says that one shouldn't "hang out" on Tisha Báv. But the reason given by the Beis Yoseph is not because one might forget about the aveilus but because it might lead to levity.This would also not apply to reading a newspaper.
Rav Ovadiah Yoseph Shlita rules [Chazon Ovadiah page 315] that according to the strict letter of the law it is therefore permitted to read a newspaper on Tisha B'av. However it is preferable not to do so as the Machzor Vitri writes that one shouldn't be involved in dvarim btailim on Tisha B'av. It is better to learn permitted Torah or to read a book about the Holocaust.