A terror attack is unfolding in Ottawa, Canada today and as the story unfolds people naturally feel unsafe. Canada has been an instrumental US ally over recent decades and has committed support for every major US conflict in the last 25 years.
They are also a member of the 5 eyes league of nations that surveils the world and has key access to the shared information between the governments of the United States, Australia, New Zealand, the United Kingdom, and itself in a huge repository called XKEYSCORE. This clandestine program that was revealed by the Snowden revelations gives unfettered access to huge amounts of information on people around the world. The data is gathered through a huge shell of other clandestine programs that include billions of people who are not under any suspicion, and the response to any criticism is that the program is instrumental in keeping everyone safe from terrorism.
There are a number of huge flaws with this argument:
1. The US had a claim that 52 terror plots have been foiled by the system. When a partisan group that was appointed by the Obama Administration (and very pro administration) investigated the individual claims, they found that zero of the 52 claims were legitimate.
2. There is a "needle in a haystack" problem. When you are gathering massive amounts of data on everyone around the world, there is far too much data to sift through and find what you are looking for in a reasonable timetable.
3. It is not cost effective. Spending billions upon billions of dollars on a program that doesn't prevent any attacks is simply absurd.
4. The previous 3 points assume that there is an "ends justify the means" mentality to surveillance, and ignores that it is stripping away the expectation of privacy for every citizen in the affected nations. An ineffective program that costs everyone their freedoms is flawed to the core. The famous quote (paraphrased) "Those who give up liberty for security deserve neither, and lose both" is attributed to Benjamin Franklin, and certainly applies here. The only problem with this is we are not gaining security.