Trying to help someone else out by providing an answer to their question, or by posting information that might seem relevant or helpful to the community is what makes a forum great.
However, when posting information garnered from an article or post you read somewhere else it's customary and considered good form to acknowledge the original author with a link back to the article or post you referenced.
Otherwise, it makes it look like you're trying to pass it off as something you came up with on your own and what is considered plagiarism:
"What is Plagiarism?
Many people think of plagiarism as copying another's work or borrowing someone else's original ideas. But terms like "copying" and "borrowing" can disguise the seriousness of the offense:
According to the Merriam-Webster Online Dictionary, to "plagiarize" means
to steal and pass off (the ideas or words of another) as one's own
to use (another's production) without c r e d i t i n g the source
to commit literary theft
to present as new and original an idea or product derived from an existing source
In other words, plagiarism is an act of fraud. It involves both stealing someone else's work and lying about it afterward.
But can words and ideas really be stolen?
According to U.S. law, the answer is yes. The expression of original ideas is considered intellectual property and is protected by copyright laws, just like original inventions. Almost all forms of expression fall under copyright protection as long as they are recorded in some way (such as a book or a computer file)."
http://www.plagiarism.org/plagiarism-*0*/what-is-plagiarism/
Plagiarism is not only considered fraud, it makes it look like you couldn't come up with an original thought and are trying to appear intelligent or knowledgeable of the subject by passing off the work of else as your own. On several occasions people have posted word-for-word, or with trivial changes to wording, sections of an article or post they found somewhere else on the web without providing a link back to the source. Something that should be embarrassing when it comes to light, and has here multiple times, or I wouldn't feel the need to post about what should be common knowledge to everyone.
So lets all try to be productive and make this a forum worthwhile of being a member of.