J.R.R. Tolkein wrote a series of novels about a ring so powerful all would kill to possess it. Only the purest of heart could, not use it, but carry it until it could be destroyed. Tolkein based the most obvious power of the ring, that of invisibility, on the Ring of Gyges. This ring, so the the myth goes, allowed it's wearer to vanish. With this, Gyges could watch and listen unseen to whomever he desired. With it he could kill without his target even knowing he was there. Plato argued that with such power no man could resist temptation and remain just.
The NSA's PRISM program (and other related programs) means this: with a couple mouse clicks someone at the NSA can know whom everyone reading this article is. From there a couple more mouse clicks will tell them where you are and where you have been (cell phone metadata) and whom you associate with. Every phone call you have made has been monitored. Every e-mail you have sent. Every purchase you have made with a credit or debit card. The government, if it desired, could with PRISM make a list of all the activist members of a political party. Maybe it arrests you. Maybe it threatens to send your boss a summary of your porn viewing habits. Or maybe it looks for local leaders whom are having financial difficulties and insures they find jobs on the other side of the country, destroying a political movements cohesion.
PRISM is something that should never have been built. Its very existence is a threat to this country. While it exists no political party or social movement can know that it has lost fairly at the polls. Every single political leader in this country must confront that, compiled or not, the government possesses a complete dossier of all their doing.
PRISM is so powerful that any party in power, even if they can trust themselves to use it wisely, dare not let the opposition take that power for themselves. Further, any party not in power must logically fear PRISM so greatly that it does everything it can to seize power and thus control of the program. Faced with an opposition using increasingly escalating and desperate tactics, the party in power will be sorely tempted to use PRISM as a way to curb unrest. The very existence of the PRISM program is an invitation to a constant series of escalating power struggles. This cannot end well.
For the good of the country the PRISM program must end and its databases must be destroyed lest it destroy us.