The government wants this data in order to maintain control over a population of millions of people whose democracy prohibits the authoritarian spying and oppression which can be found in Russia or China.
It allows the United States government to exploit weaknesses in individuals or the entire population when they have so much information.
The only question which is critical to consider is why a person should care if you they "nothing to hide". Glenn Greenwald, the journalist who was first contacted by Snowden, gave a TED Talk on the topic http://www.ted.com/talks/glenn_greenwald_why_privacy_matters...
I don't think there is a conspiracy of control. I think the people involved in creating these programs are true believers who think they are making the world a better place.
The idea that it is being done to maintain control creates a nexus of evil, a boogeyman that is responsible for it all. The idea I propose, that the only thing behind it is basic human nature, is much scarier.
The people in charge of these programs believe in the United States Government, not the nation, not the people not the constitution, but the government
They believe that Anyone that disagrees with the government at any level is the enemy and they must protect their government from that enemy even if those people are the citizens of that very nation they are suppose to serve.
It allows the United States government to exploit weaknesses in individuals or the entire population when they have so much information.
The only question which is critical to consider is why a person should care if you they "nothing to hide". Glenn Greenwald, the journalist who was first contacted by Snowden, gave a TED Talk on the topic http://www.ted.com/talks/glenn_greenwald_why_privacy_matters...
It answers your question better than I just did.