If you look at the "rapid responses" left to an opinion article published in the BMJ, you will see a response left by an individual calling themselves Brian Deer that says (in part) -
I know the names and family backgrounds of all 12 of the children enrolled in the study, including the child enrolled from the United States.I think it likely that this comment was left by the real Brian Deer as he does leave comments in random places and a story about Dr Wakefield is sure to attract his attention. Furthermore, if you happened to read some of the stories written by Mr Deer about a year ago for the Times Online, you would be able to see that he does seem to have details of at least some of the participants in the study.
So, assuming the claim is true and Brian Deer has the names, medical charts, and family histories for all of the children in the study, what does that mean?
If it was my child whose privacy had been violated, I would not be happy. I would be even less happy that it was a journalist like Brian Deer that had my child's records.
I know that in the US, it would be illegal for Mr Deer to have, much less retain, the information unless it was given directly to him by the families or the families agreed to release it to him. But seeing as how some of the the original 12 families are publicly supporting Dr Wakefield, I don't think they would have agreed to release it to him. So if this happened in the US, the matter would likely already be in court.
But this didn't happen in the US, it happened in England. I don't know what the medical privacy laws are in England, but I can't imagine that are so lax as to allow a journalist to have unfettered access to confidential medical records. Someone had to have released the records to him. I don't think the Royal Free hospital would have done it, they have a strict policy against it. So I wonder who released the records and why they did it.
It is a mystery.
One thing is clear though, Mr Deer has no right to those records and should delete all traces of them.