“What man is going to donate sperm if it might lead to a paternity suit and child support years down the line?”
Laws in Europe and in the USA shield donors from any parental obligations whether the donation is annonomous or not. The only cases where suits have hit donors is when a woman has a friend donate to her and no legal contract exists to make sure he is not obligated as a parent.
Then I wonder what sort of legal arrangement Mellissa Etheridge and Julie Cypher made with David Crosby when they borrowed his spooge for their (presumably musically-talented) child.