Singer Demi Lovato serves as grand marshal during the 44th annual Los Angeles Pride parade in West Hollywood, California June 8, 2014.
Demi Lovato entered rehab for eating disorder and self harm. REUTERS

Demi Lovato has stood up against the Internet bullies who have made fun of her half-sister, Madison De La Garza, because of her physical disability. The incident came into picture when a video grab from Madison's Vine account was posted on Twitter. The video shows Maddie in the act of cooking something and the caption simply reads "Chef Maddie, everyone."

In the video, Maddie looks completely immersed in her cooking, as she puts some ingredients in the pan. In the process her back gets exposed to the camera. [Check out the video here]. Demi revealed in her Twitter account that her sister suffers from scoliosis -- a medical condition that makes the spine curved from side to side. Some of the insensitive bunch of people called Maddie by various names on Twitter, including "hunchback" and made fun of her appearance.

This infuriated Demi and she posted a series of angry Tweets on her Twitter page, blasting the cyberbullies. The 22-year-old said that she can tolerate when anyone bullies her on cyber space as she is a celebrity but when it comes to her "baby sister" she will give it back to anyone who does that.

Demi reportedly sent direct messages to all the people who posted nasty comments about her 12-year-old sister and told them to "shut the f--- up." She reiterated the fact that physical disability is something that is not in person's control and no one should make fun of anyone's condition, as it can possibly lead to extreme steps like "suicide" by the victim of bullying.

"Physical disabilities are NOTHING to joke about. SEVERE SCOLIOSIS IS NOTHING TO MAKE FUN OF," said Demi in one of her Tweets. She added that her sister had done nothing to any of those cyber bullies so she should not be made fun of too. Demi further called Maddie as "beautiful" and assured her that she will always be there to "protect" her. Check out few of her Tweets below:

#MADISONISBEAUTIFUL #FeelBetterMaddie... True Lovatics - GO!!!! I love you guys.. You have the power to cheer her up.. we love you

— Demi Lovato (@ddlovato) September 1, 2014

For anyone telling me to "chill".. The impact bullies have over the internet can lead people to suicide. I ... http://t.co/SbLRdbdQED — Demi Lovato (@ddlovato) September 1, 2014

"#MADISONISBEAUTIFUL" and "#FeelBetterMaddie" started trending on Twitter after Demi's angry outburst. She urged her "true lovatos" (true fans of Demi Lovato) to support her sister by Tweeting against cyber bullying. Many of Demi's fans showed their support to Maddison by cheering her up after the incident.