If a newbie asked a very simple question, He tends to be blamed like this one I want to get data by the current URL, so I have set a post value, but it is set for all pages.
Questions describing a problem that can't be reproduced OR seemingly went away on its own (or went away when a typo was fixed) are off-topic as they are unlikely to help future readers has some truth.
But, newbie often run into some very simple problem like typo or lack of basic understanding, if nobody help them, them will never get out and lose passion for Magento. We are all growing up from newbie and newbie is important for a software growing and promotion. I think we should be more friendly and more inclusive.
And, the specific problem like I given maybe can't be reproduced, but some other newbie might meet a similar problem, and get inspired form the question. So why don't we just let the question be there? Give newbie a good mood and positive feedback, promote them back to use our Magento and our site :)