A seemingly harmless photo of Mark Zuckerberg and his newborn daughter Max at a doctor’s office drew much ire from anti-vaccination parents.

The 31-year-old Facebook CEO, who first got on anti-vaxxers' bad side when he recommended a book supporting vaccination last year, shared a picture of himself and his daughter on Friday with the caption, "Doctor's visit — time for vaccines!" Since it went up, the photo has received more than 3 million likes, and more than 67,000 comments, "debating the importance of vaccinating one's children" from Facebook users, The New York Daily News reported. The majority of comments show support for Zuckerberg — one woman thanked Zuckerberg for posting the picture and sending a positive message: "Thank you for posting this! As a mom to a child that was vaccine delayed due to health reasons, I am so appreciative to those parents that do vaccinate. For five years, I had to rely on other parents doing their part to keep my son healthy. Vaccines save lives and not necessarily just your child's."

Others have thanked Zuckerberg for "doing what's right and also showing everyone else that [getting your child vaccinated] is the right thing to do as well" —but then there are those opposed, like anti-vaxxers. The latter group took the opportunity to use Zuckerberg's own site to shame him for vaccinating his newborn, and weigh in on the potential side-effects of vaccines, US Weekly reported.

"Injecting newborns and infants with disease and neurotoxins is disgusting science that injures millions every year," one comment begins. "Autism, encephalitis, brain damage, auto immune disorders early onset & late, asthma, allergies, add/ADHD, bipolar disorder, SPD, pandas, Tourette's... All of these neuro disease in the past 35 years. Do you homework. The only thing these children have in common is the VACCINE SCHEDULE! That's it. Period."

Another woman asked, "Why would you subject your wee little one to vaccines?!? I know your wife is a pediatrician but did you do your research on vaccines? I've seen, firsthand the results of vaccines and it isn't worth it! Btw, I'm a retired R.N.,” according to NY Daily News.

One anti-vaxxer went so far as to say the entrepreneur and philanthropist, who reportedly boasts a net worth of more than $40 billion, was profiting from posting this photo.

The backlash prompted pro-vaxxers to chime back in.

"What kind of parent are you? Putting life saving [chemicals] in that baby! You'd think you loved her or something. Nonsense! Her natural baby tolerance and resistance is all she needs to fight crippling polio and life ravaging tuberculosis!" one comment read.

People against vaccination maintain ingredients used in vaccines cause autism, but the Centers for Disease Control and Prevention and other health officials have said there's no link between autism and any vaccine or vaccine ingredient. And as reported by Tech Times, not only are vaccines considered safe and effective, but it reduces the number of vaccine-preventable diseases.

"Some vaccine-preventable diseases often lead to prolonged disabilities," Tech Times said. "These diseases can take a financial toll on families because of expensive medical bills for long-term disability care, experts said. Getting vaccinated is a good investment and is usually covered by insurance. The CDC's Vaccines for Children Program provides vaccines to children from families with low incomes."