Governments are elected to represent and serve the voters who put them into power.
Sometimes they forget the represent and serve and only enjoy/use the power and to have to wait 4/5 years for voters to register their protest at election time can be just unacceptable, to a non-listening goverment. The frustration and anger buildup, and slow or non-action by the government of the day needs a very distinctive wake-up call to set things right.
When one reads that during just the six weeks following little Sarah's demise, over 400 paedophile/child molestings were reported, it shows that not only should government(s) have previously acted, but should right now.
If pressure from the public makes a change, then this is not only worthwhile, but highly commendable and it is certainly time.
The issue of tax on fuel, with Britain having the highest in Europe, if not the world, it is one argument from the government that tax collected goes to schools, hospitals, police, etc; but if education standards are falling, waiting lists and services in health care are appalling, and police have to hold back at events like Notting Hill where murders are committed, and the crime rate rises, the excessive fuel tax (amongst others) is being seriously mis-spent. People who waste other people's money have to expect to be made accountable, and fuel prices affect everyone in all walks of life.
So, if this very un-British action, ie, peaceful but effective demonstrations/protests moves the present complacent government (with their huge majority who can effectively oppose them), and makes them realise what their job is, to represent and serve, then let there be more of them.