And from the second article (an op-ed by a Congressman):
>Neither program allows the NSA to read e-mails or listen to phone calls of American citizens.
This is blatantly false, and the Government has said as much. The entire article is a mixture of falsehood and slick (read: dishonest) reasoning.
The first link is more unsubstantiated than the submitted link.
And the third link is a tweet about what a Congressman said.
The only one that has any helpful information is the Washington Post article and it's just a statement offered without evidence.
In case you didn't know, primary sources would be things like internal memos, pictures, videos, etc that are related to programs like Prism. E.g., the evidence offered by Edward Snowden and not in any of the links you posted.