If you actually take the time to look at some of the material that has been published and ignore the hype people like greenwald put in to push their point of view rather than report on what is actually there you would actually see a lot more protections and checks than is being reported generally.
Also it is amazing how often after some sensational article comes out, when it gets more scrutiny it turns out to not really be all that damming. Probably the most telling thing is that even with people going out of their way to look for evil intent they have so far only shown the possibility of abuse, not the actual large scam systematic abuses everyone worries about.
Yes, there appears to be some large scale collection programs, but in today's world it does not seem like there is any way to do intelligence gathering any other way. This is not the 40s where every phone call occurred on its own individually hand switched circuit anymore. And phone calls now are really just a minor part of what is going around.