The Home Office has given a response to Facebook's assertion that monitoring all communications on social-networking sites would be overkill.
The Home Office sent me a statement yesterday evening:
"The government has no interest in the content of people’s social network sites and this is not going to be part of our upcoming consultation. We have been clear that communications revolution has been rapid in this country and the way in which we collect communications data needs to change so that law enforcement agencies can maintain their ability to tackle terrorism and gather evidence. To ensure that we keep up with technological advances we intend to consult widely on proposals shortly. We have been very clear that there are no plans for a database containing the content of emails, texts, conversations or social networking sites."
This statement is more than a little disingenuous. What the government wants, for law enforcement or otherwise, is traffic data. In the case of social networking sites the government wants to know who is communicating with whom, at what time, and, if possible to ascertain, at what geographical location. Same with VoIP communications, IM, email, and all telecommunications. Oh, and to monitor all UK citizen web surfing habits too.
So no, the government doesn't want to record the content of these communications -- if they wanted to intercept individual communications they can already do that under various pieces of legislation, including the Regulation of Investigatory Powers Act. The government wants the traffic data, which will enable them to track any UK citizen by location and time, and chart their network of friends, acquiantances, colleagues, and other social contacts.
The reason why the government wants this information has not been made very clear -- vaguely it is touted as an anti-terrorism measure, and to help police gather evidence.
Presumably the present government wants that information to be able to data-mine after a terrorist attack has taken place, and find the links in the terrorists' network. The thing is, any vaguely tech savvy terrorist or criminal will be bouncing encrypted communications through various proxies in different jurisdictions anyway. And if they themselves don't possess the necessary skills, they will pay people who do. This measure would only be really useful against fools.
Weigh that against the dangers. Tracking everybody's communications all the time would certainly be an invasion of UK citizens' privacy, and may possibly contravene European human rights law. And how dangerous this becomes really does depend how benign future governments are. Ask any network security theorist: once you have identified the nodes with the most connections in a network, if you want to disable or destroy that network then you disable or destroy those nodes. Pretty basic network theory, but what if the network is a politically dissenting group, or any group a future government finds unacceptable, and you are that node? Effectively what the government wants to put in place, combined with information on other government databases, could make it very easy for a totalitarian regime to arise. And hey presto, the terrorists would have won.