She thrust the letter at Harry, who saw that it was not handwritten, but composed from pasted letters that seemed to have been cut out of the Daily Prophet.
You are a WickEd giRL.
HarRy PotTER desErves BeTteR.
GO back wherE you cAMe from mUGgle.
“They’re all like it!” said Hermione desperately, opening one letter after another.
“‘Harry Potter can do much better than the likes of you. . . . ’
‘You deserve to be boiled in frog spawn. . . . ’ Ouch!”
She had opened the last envelope, and yellowish-green liquid smelling strongly of petrol gushed over her hands, which began to erupt in large yellow boils.
“Undiluted bubotuber pus!” said Ron, picking up the envelope gingerly and sniffing it. Rowling, J.K. Harry Potter and the Goblet of Fire (pp. 218-219). Pottermore Publishing. Kindle Edition.

Harry drew his wand and literally froze the owls and the letters they carried where they were. “Dobby!”
Dobby popped up immediately.
“Get Hermione to the ICW Infirmary, along with this letter. Careful it has bubotuber pus on it. And tell them Heir Peverell-Potter is demanding an investigation into the bio-terrorism attack during the breakfast hour at Hogwarts.”
He pointed at the owl that delivered the letter as well. “And take the owl as well.”

Dobby popped off with literally everything frozen and Hermione with an angry pop.

Harry looked at the shocked staff, “Master Flitwick if you would be Champion to my cause?” He got a nod. So, Harry summoned a messenger patronus and gave it a message to trumpet up and down the Alley for as long as it could. And as loud as it could. Pumping energy into it.
“RITA SKEETER! YOU ARE HEREBY CHALLENGED TO MEET MY CHAMPION, MASTER FLITWICK OF THE CLAN WICK THIS EVENING AT HOGWARTS FOR A DUEL OF HONOR!
“YOU HAVE HARMED MYSELF AND THOSE CLOSE TO ME WITH YOUR GOSSIP-MONGERING. AND MUST NOW PAY EITHER IN BLOOD OR IN WERGILD OF FIVE THOUSAND GALLEONS AND A CONTRACT TO NEVER WRITE AND HAVE ANYTHING TO DO WITH ME OR MINE AGAIN!
“IF YOU DO NOT SHOW AND STAND BEFORE MASTER FLITWICK OR HAVE YOUR CHAMPION SHOW. I WILL HAVE THE GOBLINS TAKE THE MONEY FROM YOUR ACCOUNTS AND BRAND YOU A LIER AND CHILD ABUSER!
“Lord Harry James Peverell-Potter.”

The witches who sent bioweapons to the school, and Hermione, were quickly picked up by the international hit-wizards and publicly convicted of terrorism and sent to Nuremberg Prison for life.
Rita tried to escape her fate but was caught under an international warrant and tried as the mastermind of the bio-terrorism plots and also sent to prison after having her powers blocked.
The magazine was fined G5,000 for its own actions in printing the article of defamation that started it all and had to spend an entire magazine apologizing for its actions and retraction for what it said.
It never recovered and went out of business six months later.