This ideal unfortunately is not always a reasonably obtainable one. Should we make it easier for terrorists to communicate with each other so they could coordinate attacks? Should we allow for the possibility? When you shut down an ISP, free speech is delayed. It could be that those ISPs were guiltless. However the weighing of free speech versus possibly endangering lives is the same argument as not whether to allow someone to yell "Fire!" in a crowded theater if there is no fire. Perhaps the shout would do no harm. Perhaps it would. There is only so much risk we can take with free speech, but it should cause us pause when we have to curtail it.
Certain fourth amendment rights have been sacrificed lately in our own country to fight terrorism. The fourth amendment in the USA prevents illegal search and seizures in this country. Only under very particular circumstances is it waived. Now there are more ways searches and seizures can be done without consent legally. It is a cherished right here, but it's something we sacrificed a bit of to fight terrorism. Many are unhappy about it, but many more are willing to make this sacrifice and hope it's only temporary.
Ideals are fine to have, but they shouldn't be completely substituted for common sense. Are we making the right choices? Is this the start of a slippery slope that will lead to more sacrificed rights and ideals? Perhaps. We're only human and we have to make the most reasonable decisions we can.
We hope that our traditions of freedom and liberty here will prevent more rights being curtailed than necessary. We haven't always been successful in this balancing act, but the very existence of government is a balancing act.
Even ancient civilizations realized that order and liberty have to be balanced against each other. If a land has too much order, it becomes tyranny. If it has too much liberty it becomes anarchy. We've seen both happen in government systems. The balance changes depending on the era and the circumstances.
Are we balancing right this time? Only the results of our actions will determine that definitively.