People think there's something wrong with Hilary Duff's photo with her son.

Who knew trolls loved to target parents so much? And celebrities too?

In news that is almost sad in its predictability, Hilary Duff has been forced to defend herself after uploading a photo kissing her four-year-old son on the lips.

The photo, taken of mother and son at Disneyland, ignited a wave of comments and debate about whether a mother’s love for her children extended to being able to kiss them on the lips.

“I think you can show love in many other ways, but kissing in the mouth with kids/parents/relatives its just weird and sick,” one user wrote.

A photo posted by Hilary Duff (@hilaryduff) on Dec 12, 2016 at 6:44pm PST

“Freaks! Do you use a tongue as well,” another user said.

Meanwhile, one more wrote that they believed kissing children on the lips was “confusing” for the child in question.

“You should not kiss your son like that. There’s other ways to show love but not that one. It’s confusing for him, it’s not healthy.”

Despite a steady onslaught of criticism, the photo also ignited a litany of users who were totally supportive of the 29-year-old and her show of affection.

“There’s something wrong with you if you see anything inappropriate about this. There’s nothing wrong with kissing your child on the lips,” one wrote.

A photo posted by Hilary Duff (@hilaryduff) on Dec 13, 2016 at 9:09am PST

“He came from you. You literally made this child. Kiss him while he let’s you,” another pointed out.

In a separate post, Duff commented on the criticism, writing that those who found the image ‘inappropriate’ are more than welcome to unfollow her.

“For anyone commenting that a kiss on the lips with my four year old is ‘inappropriate’ go ahead and click a quick unfollow with your warped minds and judgement,” she wrote.

Duff is certainly not the first celebrity to fend off trolls after uploading a seemingly innocent family photograph.

In January of this year, former Victoria’s Secret model Alessandra Ambrosio faced similar kinds of backlash after she shared a photo on her Instagram of her two children Anja and Noah kissing. She captioned the image with, “The best kind of love”.

“This is disgusting,” wrote one. “This doesn’t look good…” thought another.  Some even when as far as to cry ‘incest’.

Anja is just 7 and Noah just 3.

These two prime examples aren’t the anomalies, either. Just a few months later, fashion designer and former queen of pop Victoria Beckham found herself front of centre of the debacle, too.

In July, Beckham uploaded a photo with her five-year-old daughter Harper. “Happy Birthday baby girl. We all love you so much,” Victoria captioned the photo of her kissing her daughter on the lips.

And the trolls came out with absolute force, unoriginal and repetitive in their banter, writing that the image was “inappropriate” and “so lesbian”.

The debate around the mother-child lip kiss isn’t new. In August of last year, Dr Charlotte Reznick, author of ‘The Power of your Child’s Imagination: How to Transform Stress and Anxiety into Joy and Success’ claims, “the kiss on the lips can be stimulating … It’s just too confusing.”

“If mummy kisses daddy on the mouth and vice versa, what does that mean when I, a little girl or boy, kiss my parents on the mouth? If I had to answer when to stop kissing your kids on the lips, it would be now,” she wrote.

Despite the criticism launched squarely at Duff, Ambrosio and Beckham, it appears those in support of an affectionate kiss are growing louder and more vocal in their efforts to silence the trolls.