Last week Irish singer Sinead O'Connor found herself among the many critics who expressed concern for "Wrecking Ball" singer Miley Cyrus. In an open letter to Cyrus, O'Connor advised the young artist to avoid sexual exploitation by the music industry. Cyrus struck back in a series of interviews and Twitter rants, pegging O'Connor as "crazy" and highlighting O'Connor's struggles with bipolar disorder.

This week the feud continues. O'Connor initiated another round in the battle on Tuesday, Oct 8, posting a fourth open letter to Cyrus on her website. In the 1,800-word memo, the 46-year-old singer criticized Cyrus' response to the initial letter, arguing that Cyrus' tactless remarks made O'Connor a victim of cyberbullying.

"No person, myself included, should wake to the types of emails and communications I have had for the last few days urging that I should kill myself," she wrote. "Nor to the type of Net abuse I have had to endure as a result of what you did."

O'Connor went on to say that Cyrus' comments not only incited the "Net abuse" but also affected O'Connor's reputation. In response to O'Connor's first letter, Cyrus tweeted: "Before Amanda Bynes … there was …" and posted O'Connor's own tweets about seeking psychiatric help. These posts, according to O'Connor, have damaged her reputation in the music industry, making it difficult to find work.

"Neither should I now have to have management write to half the show-business world to explain my tweets were two years old and that … I am very fit for work," she continued. "I have four children to support. I can't do that if people believe me to be unemployable."

For these and other abuses, including Cyrus' mocking of struggling actress Amanda Bynes, O'Connor made a list of demands. First, and foremost, she wants an apology.

"I would very much like you please to apologize to myself and Amanda Bynes for having perpetuated abuse of both of us on the grounds that Amanda has had mental health issues and that I experienced suicidal compulsion and was open about seeking help in order to save my life," she wrote.

She also requested an apology to "all sufferers of mental health difficulties and all those who have had experience of suicidal feelings or who had been affected by suicide."

O'Connor, who has already threatened to take legal action against the 20-year-old Cyrus, closed her rant by clarifying that the initial criticism of the young star was made in "a spirit of motherly care," and that she had no intention of continuing the feud, so long as Cyrus does the right thing.

"You're entitled to disagree with people. But you're not entitled to incite abuse of those perceived to be mentally ill," she said. "I find it hard to imagine you to be an entirely uncaring girl, so I hope you will prove me right by doing all I have asked of you here."