Please cite the author of any post you are making which does not belong to you. The persons who created or documented that knowledge need to be respected. If you don’t cite their work it becomes akin to theft, stealing materials and passing it of as your own a.k.a. plagiarism.
Imagine if you develop something worthwhile and someone else takes the credit. Imagine if you are an artist or author and you depend on your intellectual creations to make a living. So, spread good knowledge but give credit to the original author – VD 2015.