Re: Politicians care more about speech they don't like than stopping terrorists.
Jim (and another gentleman below), the two actually go together. Terrorism could, somewhat cynically, be described as an exercise in marketing and communications. Its effectiveness depends not on the actual damage caused, but on people's belief in the possibility of damage occurring.
This is also what has enabled certain non-State actors in the Middle East to gain an undue amount of influence in Western policy and to become incredibly successful at recruiting, at minimal cost to themselves.
Do you recall any vehicle ramming attacks during The Troubles? No? Well, they did occur (e.g., to a former colleague of mine while serving in 14 Int). They just did not merit the publicity cost, which was much higher in those pre-WWW times.
In other words, controlling the flow of information is one aspect of what is popularly called "combating terrorism". The latter being of course a massive can of worms, but that's a different discussion.