This undated photo released by the Orange County Sheriff's Office in Orlando shows Caylee Marie Anthony. (AP)

One of the sticking points of the Casey Anthony case was the fact that Anthony never notified law enforcement that her daughter was missing, which led to her being found guilty of four counts of the misdemeanor crime of lying to investigators. Caylee was last seen on June 16, 2008, but her grandmother, Cindy Anthony, didn’t notify the police until July 15, a month later.

Oklahoman Michelle Crowder, who is a mother of two daughters, says parents need to report their child’s disappearance immediately, and has started a Change.org petition and Facebook page to ask Congress to create a law to enforce that. “Caylee’s Law” would make it a federal offense and a felony for a parent or guardian to fail to report a child’s disappearance to law enforcement.

“When I saw that Casey Anthony had been found not guilty in the murder of little Caylee, and that she was only being convicted of lying to the police about her disappearance, I was sickened,” Crowder says.

“I could not believe she was not being charged with child neglect or endangerment, or even obstruction of justice.”

Nearly 2,000 people have signed the “Caylee’s Law” petition each hour since its creation, making it the fastest-growing campaign on Change.org, according to the site.

Another campaign on Facebook has nearly two million people pledging to leave their porch lights on for Caylee.

More on Casey Anthony trial

Casey Anthony verdict not guilty

Casey Anthony verdict shocks media

Casey Anthony and her court of public opinion

Photos of the Casey Anthony trial