Virgin Media is trialling a deep packet inspection system that will see 40% of the ISP's network being monitored for file sharing activity. The network plans not to inform customers that they're being monitored.

The system is called CView and is being provided by a subsidiary of BAE called Deltica, which specialises in large volume data collection and processing and usually works with intelligence agencies across the world. It'll operate at the centre of Virgin's network, and only attempt to determine the proportion of file sharing traffic that infringes copyright.

Customers are likely to be a little uncomfortable with Virgin Media handing over their emails and web browsing habits to a weapons manufacturer, but Virgin Media has emphasised that it just wants to measure the overall level of illegal file sharing, not keep records on individual customers.

BT's controversial Phorm advertising system used the same kind of technology, and also didn't inform or get consent from subscribers to the network. That proved to be a hot potato and was heavily criticized by privacy advocates and the internet community.

Virgin is preparing to launch a legitimate download service in partnership with Universal Music. "Understanding how consumer behaviour is changing will be an important requirement of Virgin Media's upcoming music offering and, should they become law, the Government's legislative proposals will also require measurement of the level of copyright infringement on ISPs' networks", said Jon James, executive director of broadband at Virgin Media.

If you're a Virgin Media subscriber, are you comfortable with this level of intrusion in your web browsing? Let us know in the comments.