To trust a person, or a news source, "blindly" is to trust it without question; without the slightest doubt that the source may be mistaken.
Example: Yesterday, I read a story called "Wired youth forget how to write in China and Japan." According to the story, young people in China and Japan - countries with very high literacy rates - are forgetting how to write with a pen, and gradually, how to even read "kanji," the Chinese characters that are the foundation of both writing systems. This amnesia is supposedly due to young people doing so much "texting" (sending text mesages) with cell phones using pinyin or kana, which function more like alphabets.
Today, I spoke to a resident of China, a Chinese native speaker, who is learning English. After answering a question of his, I mentioned the above news story. He replied, "But the truth is not like that." I answered back, "I'm used to the media exaggerating so I didn't trust the article blindly." I retained skepticism that the article was truly accurate and represented the full story.
The opposite of trusting blindly is to take something with a grain of salt, which is featured in my eBook, "Food for Thought."