Alex said that if you summarize a story in your own words that it's not necessary to cite the source, as far as following the copyright rules.
However, it's advisable to cite the source in those situations in order to allow the reader to judge the value and credibility of the source. It's an intellectual courtesy. Not a "rule" but a courtesy.
Citing sources also builds up the credibility of the poster, which most people consider a positive thing. It is also helpful to readers who might want to get more details or the full story.
Requesting sources is not disrespectful or punitive if done in a courteous manner.