"First, the transfer of private data is a significant interference with an individual's article 8 rights. That interference will only be lawful when proportionate."Secondly, the ECHR has held on more than one occasion that surveillance, and the use of surveillance data, is an area in which governments must conduct themselves in a transparent and 'predictable' manner. The current framework is uncertain: it relies on the discretion of one individual."Thirdly, on a pragmatic level,there is a real possibility that the NSA might function as GCHQ's unofficial 'backup' service. If GCHQ is not entitled to hold onto data itself, it might transfer it to the NSA. In time, and if relevant, that data might be transferred back to GCHQ. Without strong guidelines and scrutiny, the two services might support each other to (in effect) circumvent the requirements of their domestic legislation."The opinion adds: "If GCHQ transfers communications data to other governments it does so without any statutory restrictions. Such transfers are a disproportionate interference with the article 8 rights of the individuals concerned. There are no restrictions, checks or restraints on the transfer of that data."