On Monday (19 August), Chris was dropped from Corrie after he was unmasked as a vile online rapper called The Phantom.
In his YouTube videos, Chris wore a frightening Halloween mask and rapped about raping women and stabbing people with needles, among other horrific things.
Katie, who was severely scarred by her ex-boyfriend in a chemical attack in 2008, has now hit out at the actor after some people suggested his lyrics were similar to those found in other popular raps.
Taking to Twitter, she said: "Corrie St's Chris Fountain online rap isn't reflection of main stream culture or rap music, they are his unhealthy sinister thoughts on women.
"Most men wouldn't talk bout women in that way or have those strange thoughts. What makes a 25 yr old man write & sing about mutilating women?"
Moat men wouldn't talk bout women in that way or have those strange thoughts What makes a 25 yr oldman write & sing about mutilating women— Katie Piper (@KatiePiper_) August 20, 2013
On follower replied, saying: "Seriously? Get a grip!! His video has been blown out of proportion!!!"
But Katie hit back: "Singing and writing about raping and attacking women is a serious subject."
Following his sacking, Chris released a lengthy statement apologising for his actions.
In in, he said: "I am mortified that I have brought so much embarrassment to my colleagues and employers these last few days.
"My biggest regret however is not to do with losing my job, but that I have hurt and let down so many people including those in a vulnerable situation and I am so very deeply ashamed of this."