If you adopted a child who had a brother who was adopted into a different family would you let them meet?

[Daniel]

I have a brother that I havnt seen since I was three. He was adopted into a different family. I tried contacting him when we were both younger. The people that adopted him said that if I ever tried to contact him again, they would file a restraining order against me. Thanks to the wonders of facebook I have found him after 18 years of seperation. I am afraid of contacting him but I desperately want to. I am still afraid that his adoptive parents will try to stop me, should I add him as a friend and tell him our story?