Sinead O'Connor published a lengthy open letter to Miley Cyrus.  It addressed O'Connor's feelings on Cyrus' recent behavior and pop culture, overall.

In the letter O'Connor writes, "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. It is in fact the case that you will obscure your talent by allowing yourself to be pimped, whether its the music business or yourself doing the pimping."

Miley's response was not positive.

Cyrus tweeted a screenshot of Sinead O'Connor's tweets from a couple of years ago when O'Connor was openly battling mental illness.

Please be advised that these posts contain coarse language.

O'Connor responded on her Facebook page.

Miley tweeted a couple of more times.

Finally, O'Connor wrote a third open letter.