It's a battle of the singers over social media -- between pop star Miley Cyrus and Irish singer Sinead O'Connor -- and it's getting uglier by the minute, with the verbal 'wrecking ball' swinging in both directions.  

The "We Can't Stop" singer and the "Nothing Compares 2 U" singer are going back and forth over an open letter from O'Connor calling on Cyrus to tone down her over-sexualized persona.

O'Connor, 46, said she was worried that the former child TV star was being exploited in her latest video for the song "Wrecking Ball," saying: "I am extremely concerned for you that those around you have led you to believe, or encouraged you in your own belief, that it is in any way 'cool' to be naked and licking sledgehammers in your videos."

While O'Connor said that the letter came from a good place, "in the spirit of motherliness and with love," Cyrus wasn't feeling the love. O'Connor addressed comments Cyrus made during an interview with Rolling Stone that her new look and video were modeled on O'Connor's 1990 video for the song "Nothing Compares 2 U", where she sheds a single tear.

Cyrus cries in the promotional clip for "Wrecking Ball," but the tender moment is overshadowed by the singer licking a sledgehammer and writhing naked on a swinging metal demolition ball.

According to Reuters, Cyrus then mocked O'Connor by posting a screenshot of O'Connor's tweets from 2012 in which the Irish star, who has bipolar disorder, referred to her own mental health problems, asking for Twitter followers to recommend a psychiatrist. To make matters worse, Cyrus also compared the singer to the former child actress Amanda Bynes, who is currently undergoing psychiatric treatment.

O'Connor issued a follow-up open letter on her website accusing Cyrus of "irresponsible" behavior.

This isn't the first online celeb feud; Latina stars are in on it too.   

Latina Magazine listed the "9 Celebrity Feuds That We Secretly Love To Watch" -- and here are the top three:

Lorde vs. Selena Gomez: While Selena appears to be a fan of 16-year-old hipster-pop singer, Lorde, it doesn't quite seem as though the feeling is mutual. During an interview, the young singer said: "I love pop music on a sonic level. But I'm a feminist and the theme of her song ["Come & Get It"] is, 'When you're ready come and get it from me.' I'm sick of women being portrayed this way."

Selena hasn't responded to her latest critic, but Lorde has certainly been feeling the wrath of the 21-year-old's fan base. According to Idolator, Selenators have been tweeting comments such as, "I hate Lorde's music and attitude towards every other artist, I bet she's jealous of their success." They've even gone as far as uploading photos comparing the New Zealand singer to the Hunchback of Notre Dame.

Chrissy Teigen vs. Jennifer Lopez: John Legend's fiancé, model Chrissy Teigan, was not a happy camper while in attendance at Gucci's Chime for Change Awareness Concert. The model was busy behind stage watching John perform when all of a sudden, J.Lo's entourage made her leave the area in preparation for J.Lo's arrival which prompted Chrissy to go on a Twitter rant.

"I love Jennifer Lopez," she tweeted. "But as I am sitting and watching John perform, I don't need her people to lay down the J.Lo laws." Chrissy then finished off by tweeting, "I have never once been asked to leave an area for an artist's supreme arrival. Maybe I should carry around a horn and streamers. I'm bummed because I really loved her dammit. Anyhow, moving on."

Kelly Osbourne vs. Christina Aguilera: They say if you don't have something nice to say, you shouldn't say anything at all, but apparently these two never got the memo. According to Kelly, Christina would call her fat for so many years before she lost weight. "She called me fat for years," she said. "I was never that fat."

So in 2011, after Christina had put on a few pounds, Kelly got her payback during an August episode of Fashion Police. "Maybe she is just becoming the fat bitch she was born to be," Kelly said. Two months later, Christina was featured on the show again. Kelly once again shared her thoughts saying, "Lady Marmalade got into the peanut butter again." (Check out Latina Magazine for the rest.)