Of course extremists are a small percentage of Muslims. Even if you were to be extremely generous and say there are 100,000 Islamist terrorists in the world and that is a very generous figure that's still only .01% of the world's Muslims.
Most terrorist attacks take place within Muslim countries, not the West. As horrific as today is, it is still luckily very rare. Let's remember also that similar attacks like in Norway were not committed by Islamists.
There is a huge global problem to be sure but people need to keep it in perspective otherwise we will do things that will just make it worse. I agree this was a freaking gift to the FN in France and if they end up clamping down on innocent people it will just drive more people to extremism. Any response has to be very narrowly targeted against extremists and their supporters.
Also just to say that Lockerbie was not the work of Islamists, it was ordered by either Libya or Iran in retaliation for US military actions.