Question #1: NSA
Using the Multisearch, you can search for "NSA or national security agency" and "metadata" and "constitution*" Notice that I broke down the question into its different subjects, and didn't include any verbs or adjectives. I also searched for the word "constitution*" with an asterisk at the end. This is a searching trick in databases, and when you add it at the end of a root word, it will search for all variations of the word.

If you want to get back articles that actually talk about the legality of the metadata gathering, you can also under Filters choose "Source Types", which include Academic, Books, and Reports. Often news/magazine stories will only give cursory information, whereas academic or professional publications will go into more depth about a subject.
