Troubled Relationship with BP

I have a 2-and-a-half-year-old adopted son. He was removed from his birth mother’s home by DCS when he was 2 months old and placed in foster care after the birth mom told them there was no family. I was there the week just before the baby was taken asking if I could have temporary custody, because I knew the birth mom was struggling with multiple drug addictions and prostitution. My brother (the birth father) was in jail at the time. Long story short, my husband and I filed for custody and ultimately the birth parent’s rights were terminated. We have a “closed” adoption. My brother signed his rights and the state terminated the mothers. The birth mother showed up to one visitation in the beginning (2 years ago) and has never called, emailed, or written since. My brother is out of jail and back together with the birth mom, and now they are posting pictures of my son online as if he lives with them (pics obtained through a family member). I received a call from my brother saying that he wanted monthly visitation and angrily spitting that we owed it to him and the birth mother. I know that they are using the photos as a way to attract attention and to find some common ground in their rediscovered relationship, and I am angry. I am furious that they would use my child for "likes" and expose his sweet pictures to their network of gang members, drug dealers, pimps, etc. In November, they posted a link to his school photos which provided the name of his school. I am scared for my son’s safety and our family’s peace, worried that they are plotting to show up in our life with bad intentions. I feel like I am losing my mind constantly replaying the worst-case scenario over and over again. I need to know that I can protect my family, and I need to find peace so I can be present with my son and husband. I need to know that I owe them nothing until I can have complete confidence that their intentions to have a relationship with my child are complete altruistic and the drugs and crime are way (way!) in the past. This has created tension with my parents – they live close to my brother and he is showing up asking for pictures and information. I hear it in their voices that there is always something they are not telling me, because they know how hard this has been on my heart and mind. I didn’t ask a specific question, but I would love some feedback.