A recent decision by the United Kingdom's High Court has called into question the assumption that the use of facts and figures gleaned from a physician's prescription data does not constitute a breach in confidentiality. The May 1999 court case in London is thought to be the first to deal with patient information that has been rendered anonymous. Mr. Justice Latham ruled that patients' implied consent covered use of their data for treatment and related purposes only, not for sale to pharmaceutical companies. The case arose after Source Informatics, a US-based company that operates a prescriber database for pharmaceutical companies, sought to approach GPs with promotions and information about their products. The GPs had refused to allow their prescription details to be supplied to the database. Source Informatics was given permission to appeal the judgement because the ruling "raises issues of huge importance for the law of confidentiality."