Biz Stone, co-founder Twitter, Inc., gives the keynote speech at the 140: Twitter Conference LA in Los Angeles September 22, 2009. REUTERS/Phil McCarten

Alas, the reigning champ of Twitter vitriol has decided to hang up her boxing gloves.

Courtney Love has closed down her Twitter account just days after her daughter, Frances Bean Cobain, went after Ali Lohan -- Lindsay's sister -- on the micro-blogging service. Mother and daughter are both tweet-obsolete for the moment.

The development occurs as Miley Cyrus raps a good-bye ode to Twitter on YouTube and her father, Billy Ray Cyrus, tries to guilt her into staying on Twitter.

Despite its popularity for public figures looking to control the conversation with their fans, Twitter hasn't been all fun and games. Love is dealing with a defamation claim after tweeting disgust at a fashion designer, and Demi Moore and Perez Hilton were also exploring legal action after their war of 140 characters or less with each other last month.

The law on what you can and can't say on Twitter hasn't been refined yet by a court, but assuming it follows the general defamation book, it'll be hard to win a defamation lawsuit. But that won't stop many plaintiffs from trying.