Are (brush/texture/etc.) "freebies" really free?

I have found lots of "freebies" (brushes/textures/etc.) on design websites/blogs that say they are free for personal and commercial projects. They usually link to texture websites, brush websites or deviantart pages. However, after downloading one I read the "readme" and it said it was non-commercial. So, who do I trust? The design blog? Or the author?