For the fans of our favorite trash journalist, Rita Skeeter.
Harry first encountered Rita when she was planning to write an article about the Triwizard Tournament in Harry Potter and the Goblet of Fire. He didn't give her the kind of answers she wanted in the interview (which took place, oddly enough, in a broom cupboard).
Her article about the tournament turned out to be mostly about Harry. A picture of Harry's face took up the front page, and she replaced Harry's answer in her interview with those of her own invention. The other Triwizard champions' names (misspelled) were squeezed in at the end of the article, and Cedric Diggory (the other Hogwarts champion) wasn't mentioned at all.
She made life very hard for Harry, and Dumbledore banned her from the grounds. Rita interviewed Hagrid, but rather than talking to him about his creatures, which he had been led to believe she would be interested in, she just wanted information about Harry. Hagrid commented after the interview that she seemed disappointed when he said that he'd never had to tell Harry off.
Rita Skeeter, who was, in fact, an unregistered Animagus who could turn into a beetle, decided to get revenge on Hagrid by coming to Hogwarts during the Yule Ball, and spying on him while transformed into a beetle. She overheard Hagrid tell Madame Maxime that he was half-giant, and printed a story about it, which made him extremely unpopular, due to the well-documented ferocious nature of giants. With the addition of Malfoy's hippogriff incident, she made it seem as though Hagrid were dangerous -- so much so that Hagrid became severely depressed and nearly resigned.
When she encountered Harry, Ron and Hermione in Hogsmeade, Hermione insulted her; and, predictably, Skeeter wrote a horrible story about Hermione, making her out to be an ugly but extremely intelligent witch who used illegal love potions to satisfy her taste for celebrity wizards, such as Harry Potter and her boyfriend, international Quidditch star and Durmstrang Triwizard Champion Viktor Krum.
Rita's last defaming article stated that Harry was "disturbed and dangerous", using comments made about him by Draco Malfoy and Malfoy's cronies. She also cited Harry's ability to speak Parseltongue (the ability to speak with serpents), and pains in the scar given to him by Lord Voldemort, as additional material for her article. This was later used for the base of the Ministry of Magic's smear campaign against Harry.
Since Rita had defamed her, but more so because of her treatment of her friends (particularly Hagrid), Hermione had been bent on finding out how Rita was spying on private conversations. She found out, and trapped her (as a beetle) in a jar, just as Dumbledore was reforming the Order of the Phoenix, thereby preventing her from revealing the Order existence to the wizarding public and the Ministry.
Hermione made Rita swear to "keep her quill to herself for a full year" or she would tell the authorities she was an unregistered Animagus and Rita became unemployed.
About a year later Hermione forced her to interview Harry about Lord Voldemort returning and to submit the story to The Quibbler.
Until then, almost nobody in the general wizarding public believed that Voldemort had risen again, due to, ironically enough, the smear campaign started by Rita herself. The article helped Harry and his friends greatly; particularly because Dolores Umbridge banned it from Hogwarts, in an attempt to stop the information in the article from spreading. But this attempt backfired; because all the students at Hogwarts became desperate to read it, to see why it was banned.