Not so long ago the idea of cyber-war was risible - something you might find in a bad 1990s movie (or a very good 1980s one), perhaps, but not in the real world.

But recently, attacks on the countrywide networks of Ukraine and Estonia, whether they were led by other countries or by organised crime networks, almost certainly constituted attacks on sovereign states, effectively fulfilling the definition of cyber-war.

Then came reports of the so-called Ghostnet, a spy network discovered in March by a monitoring group who'd been contracted by the Tibetan government in exile, itself concerned that its network had been hacked.

Ghostnet has apparently inflitrated political and economically sensitive networks all over the world, including those of embassies and governments. It operates out of China and much of the press coverage has pointed the finger at the Chinese government, although it could just as easily be run by a large-scale criminal organisation inside the country.

It may sound implausible, but it's been known for what you might call 'concerned interests' to undertake attacks, often using quite sophisticated social engineering to get to people working in the area.

For instance, the discussion on Ghostnet over at Metafilter uncovered a fascinating comment by someone who's been attacked in this way:

I could go on for pages describing various things we have seen over the past two/three years, but you get the gist. For small NGOs like mine, protecting against infiltration, monitoring our systems for intrusions, and educating our staff to recognize potential hazards has become a huge drain on our already limited resources. The frustrating thing is that there is pretty much nothing we can do about it, except to remain diligent.

In unrelated news, earlier this week, the British intelligence service put word out that it may have allowed the Chinese government access to infiltrate its own secure networks. Apparently the government's telecoms provider BT subcontracted some work on a new network to Huawei, which is thought to have been partly funded by the Chinese state. As with all such allegations, little is clear, although according to one report GCHQ warned the government about the danger of attack through the network.