They are giving credit to where ever they got their information.
Mark Zuckerberg would do anything he can to influence young people to pick up and engage in social networking in order to make a profit for his social networking business.
Poe creates contrast in his portrayal of the bird in "The Raven" by placing the black bird on the marble statue. The contrast between the darkness of the bird and the whiteness of the statue is quite striking, exactly the thing he wanted to achieve.
In Shakespeare's Romeo and Juliet, Peter-- the Capulet servant-- wanted the musicians to play a happy tune because he wanted to ease his sorrowful heart. However, the musicians refused because playing a happy tune would be inappropriate.