There was general outrage when CCTV footage of a cat being put in a bin was posted on the internet.
Darryl Mann, owner of tabby cat Lola, had posted the video on his Facebook page when he realised his camera had caught Coventry woman Mary Bale first stopping to stroke his cat, then putting her in the wheelie bin. Lola remained trapped there for 15 hours.
He put the images online in a bid to track down the woman who had tormented his four-year-old pet.
Within hours hundreds of angry messages had been posted online, the video spread quickly around the internet and Bale was eventually tracked down.
Internet group 4chan made a spoof video, featuring a cat putting a woman in a bin.
A Facebook group calling for Bale's death had to be removed.
Eventually Mr Mann and his wife Stephanie issued a plea to people to leave the matter in the hands of the RSPCA and the police.
Bale has now admitted causing unnecessary suffering to the animal.
Katy Geary, a spokeswoman for the RSPCA, said the video had caused huge revulsion around the world.
She thought it was the fact it was an ordinary woman who committed the act that had caught people by surprise.
"People assume animal cruelty might be carried out by people wearing a hoodie for example and it is not always the case.
"You can have people from all walks of life.
"What was disgusting was the reaction and anger to this, which then became threatening.
"Things have to be dealt with sensibly. When it gets to people making threats themselves then it becomes disturbing."
Although the sight of ordinary-looking Mary Bale committing animal cruelty may have shocked people, videos of animal cruelty on the internet are all too common.
"We are aware of videos being put up deliberately by some people who, for want of a better expression, get their kicks out of it.
"Dog fighting for example. But, it can help us to prosecute," said Ms Geary.
She cited videos where an animal gets trodden underfoot as an example of something which took off a few years ago on the internet.
"It started off with small creatures such as worms, went on to to goldfish and then onto larger animals in a very cruel way.
"Luckily, I am happy to say I am not aware of any examples now.
"As with happy-slapping videos (in which people are filmed being attacked by others) I don't know the reasons and I don't think we will ever understand why it happens."
Professor Ellis Cashmore, a media expert at Staffordshire University, said the fact most people were animal lovers was one of the reasons for the videos spread so fast across the internet.
"How many people have cats? There are people all over the world with cats, it is not specific to the UK.
"Plus, in general, people are kind to animals, not cruel," he said.
People will have heard about the footage, logged on and then passed it on, he said.
Another reason for the footage spreading so quickly was the almost theatrical quality of it, he added.
"You can see the woman very clearly and it almost looks choreographed as she takes furtive glances and then puts the cat in the bin," he said.
And, after watching the video, people will start to consider the ramifications, he added.
"She must have realised that bins get emptied into trucks," he said.
"It could have been horrifying."
Years ago, cruelty to animals was seen as sport, he said.
"It shows how sensibilities have changed."