Horrible, and it puts everyone on edge. Many trips and holidays affected I'm sure too.
The only thing I can say is that as an act of sabotage/terrorism at least there was no loss of life. This might however be a new trend, to disrupt daily life without any injury to the public. Who knows?
I'm watching BFM tv live from Paris at the moment. The signal boxes were set on fire, affecting TGV all over the place. The Eurostar was mentioned too as being affected. Even if Brits are not going to the Olympics that will have a knock on effect on travel elsewhere of course.
SNCF hope to have things slowly back to some sort of schedule by 1.0c. today. That's some progress very quickly I think. But let's see.