Not posting any details about my son on social media

So about a month ago a guy that I was really good friends with in high school got arrested for child pornography.. when I found this out I was so in shocked.. we know each other since 7th grade and we use to hang out all summer long.. so when I found this out I was in complete shock... when I told my mom she like “ I told u, u never truly no anybody so u always gotta be careful with what u post on social media”. So I said your right. I sent out a group text message to my family and my husband family saying how I don’t want any information or pictures of my son on any form of social media.. I had explained to them why as well and my family was like ok. We understand, my husband and his family created all this whole fight on why and they can post what they want because it’s there social media accounts and they know that none of their friends aren’t that sick in the head.. I try to explain to my husband more and my fears about it and he still isn’t understanding... I’m not sure what to do or how to get them to understand