WARNING: This story contains graphic images.
Thousands of Australia's animal lovers are rallying behind a petition which urges classifieds website Gumtree to ban ads offering free pets.
Melbourne woman Casey Kemp after spotting a number of 'horrific' cases of animal abuse documented on social media.
"I follow a lot of rescue groups and there were a few I'd seen recurrently posting about animals given away on Gumtree for free, and later they'd been found killed, tortured and dumped," the 23-year-old told SBS.
"I thought to myself why isn’t anyone doing anything about this?"
The petition has so far gathered 130,000 signatures, with the goal of reaching a further 20,000 people.

The Change.org petition calls on Gumtree to ban the advertising of animals for free. Source: Supplied
Ms Kemp said she wanted Gumtree to stop sellers from posting 'free to good home' ads because it does not have the ability to monitor who collects the animals.
Other major online marketplaces including eBay and Facebook have already banned live animal sales.
"I was actually going on Gumtree every day scouring the site for these free ads and messaging people personally saying 'there's better ways to do this'," she said.
In a statement, Gumtree told SBS it is considering updating its policy.

Melbourne animal lover Casey Kemp, 23, has warned pet owners not to give away dogs and cats for free. Source: Supplied
“Animal welfare is a huge priority for Gumtree, and we are currently in the process of a review of our policies," a spokesperson said.
"As we work through these changes, we strongly encourage our community to use the ‘report ad’ function to flag any concerning ads or any they believe do not adhere to our pets policy."
Dog fighting rings on the rise
Humane Society International estimates about 150 suspected dog fighting rings are operating across Australia.
Fights have been known to include purses totalling more than $700,000 and the cruel practice is closely linked to many other forms of illegal crime such as drug and weapons trade, violent criminal activity, and child pornography.
"Professional dogfights generally are held in extremely private locations with attendees often never even provided the actual address, but instead led to the fight location from a secondary meeting point," HSI campaigner Rhiannon Cunningham said.

An injured dog found in a raid at a property in Queensland. Source: RSPCA
"Attendees might also be made to turn off and surrender their mobile phones until the fight is over."
Animal advocates warned many underground dog fighting rings looked for free animals online to either use as fighting dogs or live bait.
Brisbane man Jared Nathan Trenear was jailed for six months in August after being found guilty of participating in illegal dogfighting.
The RSPCA discovered four adult dogs restrained with wire, no suitable bedding, and no access to clean water, as well as two litters of puppies, at Trenear's home in April 2018.

Two dogs were seized by the RSPCA from Jarred Trenear's Mount Cotton home. Source: RSPCA
HSI’s Senior Specialist in Global Anti-Dogfighting, Animal Protection and Crisis Response, Janette Reever, recently joined Australian enforcement officers at strategic meetings in Sydney and Brisbane on how to expose and eliminate dog fighting rings.