Re: At least we know...
Building a particle accelerator is a tad on the expensive side. The cheapest and most effective way of taking out satellites was posited by Arthur C. Clarke a few years ago: you get an experimental hobby rocket (for example I saw one in a specialist hobby shop for about $AUD6000 / 2500 quid that could reach a height of 200 miles) and pack a payload of about half a kilo of ordinary fine gravel or coarse sand into it, with a pressure sensor mounted on it. When the rocket reaches the required altitude, the pressure sensor triggers an explosion in the combustion chamber, scattering the sand along the orbital path of the satellite. At orbital velocities, that sand is like a meteor storm; even a few grains hitting a satellite at 20,000 kmh are going to destroy it. And this is a non-discriminatory weapon - it will destroy ALL satellites in its path, not just military ones!
Of course, launching orbit-capable rockets from a UK back yard is likely to raise the ire of the local constabulary rather quickly, but here in Australia we have millions of square miles of outback we can launch rockets from, and be hundreds of miles away from the launch site before anyone notices. Of course, there'd be some pretty high-powered suits hunting down the beggar that was launching gravel-packed rockets and taking out every satellite in orbit, not to mention giving Earth a ring system like Saturn's in the process... but it does mean even a third-world camel-jockey theocracy could take out satellites for a few grand if they really wanted to! ;)