Singer Katy Perry didn't expect that an honest and harmless opinion she posted on the micro blogging site Twitter could get her into trouble.

On May 24, the 17-year-old rapper from Chicago Chief Keef furiously lashed at her after she posted a feedback on Keef's song "I Hate Being Sobber."

The song hears Keef talk about the drinking habits of Americans and how none of them are ever sober. Perry, who is known for her family-friendly image, obviously didn't think the same way and thought that it was such a sad statement then voiced her distaste over the song.

"Just heard a new song on the radio called "I Hate Being Sober" I now have serious doubt for the world," Perry tweeted.

The effect of that tweet caught Perry off guard as the teenager Keef violently erupted days after, dishing out threats and vile words against the pop star.

"Dat bitch Katy Perry Can Suck Skin Off my Di*k," he tweeted. "I'll smack the shit out her."

After threatening to attack Perry, he next scared her by saying he was going to record a new song targeting the 28-year old Firework singer.

"New Song Katy Perry Coming Soon," he posted.

Seeing all the hostile messages on Twitter, Perry opted to not further aggravate the situation and antagonise a man who has quite an image for his violent tendencies and misbehaviour.

The pop star immediately apologised and tweeted: "Mr. Keef! I'm sorry if I offended you. I heard a lot of people guesting on the song & didn't even know it was you in particular. Actually...

"I'm a fan of your "Don't Like" video tbh. I was really just having a general opinion on our generation's desire to be constantly intoxicated."

"Believe me, I'm a lover not a hater," she posted.

Perry's tweet proved to be effective as Keef was soon apologising for his tweets as well: "Oh, I'm sorry too then," he said.

The teen rapper is no stranger to criticisms and has had consistent bad press throughout his young career. In the past, he was slammed for rapping about "threatening to murder a woman who refuses to perform oral sex on him," and has also been accused "of hiring a hit on a fellow rapper."