Miley Cyrus does not seem to have taken Sinead O’Connor’s open letter and words of advice to her in the spirit in which they were intended after she posted several mocking tweets about the Irish singer yesterday.

O’Connor has responded with a second letter in which she challenges Cyrus’s behaviour and says “It is not acceptable to mock any person for having suffered.”

Cyrus tweeted that she was too busy to write a letter in response as she’s hosting Saturday Night Live this week.

She then began mocking O’Connor by posting a screen-shot of a Twitter account in Sinead O’Connor’s name with the caption, “Before Amanda Bynes . . . There was . . . ”

Bynes was recently diagnosed with bipolar disorder.
 Cyrus also posted an image of O'Connor on Saturday Night Live in 1992 tearing up a photograph of Pope John Paul II.

In her second letter to 20-year-old pop star, O’Connor said: “You have posted today tweets of mine which are two years old, which were posted by me when I was unwell and seeking help so as to make them look like they are recent. In doing so you mock myself and Amanda Bynes for having suffered with mental health issues and for having sought help.

"Remove your tweets immediately or you will hear from my lawyers. I am certain you will be hearing from all manner of mental health advocacy groups also. It is not acceptable to mock any person for having suffered."