Looks like Miley Cyrus struck a chord with Sinead O'Connor when she replied her open letter with a screenshot of her old tweets. That stunt may just see her at the receiving end of a lawsuit.

In another open letter published on Sinead O'Connor's Facebook page:
Miley… Really? Who the fuck is advising you? Because taking me on is even more fuckin’ stupid than behaving like a prostitute and calling it feminism. 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.

...have you any idea how stupid and dangerous it is to mock people for suffering illness? You will yourself one day suffer such illness, that is without doubt. The course you have set yourself upon can only end in that, trust me... Have you no sense of danger at all? or responsibility? 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.
O'Connor also states that "Ms Cyrus' lawyers will be contacted by mine regarding this matter."

But it looks like Miley's not worried:

O'Connor also posted yet another open letter in which she wrote, "I have no interest whatsoever in meeting you. You had plenty of time yesterday to abuse Amanda Bynes .. an entirely innocent party.. and myself.. who also did nothing to deserve your abuse.” Also: "When you end up in the psych ward or rehab I'll be happy to visit you.. and would not lower myself to mock you."

Let the lawsuit begin!

[E!, The Daily Beast]