Confidentiality
The whole concept of adoption is geared around secrecy and confidentiality. The adopters' identity is hidden from the birth family from the outset and the court proceedings are usually given a 'serial number' so the parties are unaware of each other. Do not be deceived by this: mistakes and cock-ups are common in the world of social work; the court procedure is muddled and information 'leaks through' without difficulty.
And how do you keep the whereabouts of the adopters secret when the Regulations require the proceedings to be issued in the court for the area in which the child resides?
Moreover it is common for a child to be placed for adoption in the same County as they originally lived in when they were first taken into care.
In practice, of course, this matters less when there is some form of contact with the birth family, which makes it easier for them to accept what has happened.
If there are problems of harassment (which fortunately are rare) the courts have a range of powers to deal with them. Here again, a specialist solicitor's help is vital.