I don't have an opinion about this particular case. However, I do feel strongly that a reporter's rights are not unlimited and that they must observe the law and respect privacy in their dealings. It is generally not desirable to tip off a target in advance that they're being investigated as that could thwart the investigation. Note a botched investigation could mean an innocent person is prosecuted. This issue is even more sensitive in issues of national security and terrorism.
I used to read "Columbia Journalism Review", a magazine about the news industry. They regularly covered issues such as this -- protecting sources, not cooperating with the government, privacy, etc. Generally, they took a very extreme position that a reporter could do no wrong and his/her work was sacrosanct and protected by the Constitution, regardless of Constitutional rights of others involved. I saw that as a "Holier Than Thou" attitude and I didn't care for it.
Now I'm not saying the "government is always right", but many people seem to believe it and then ACT on the principle "the government is always wrong and evil" and that's certainly not true either.
In WW II, people who thought they knew better gave critical military secrets to hostile enemies. Who were those people to think they knew better than the rest of us? What gave them authority over our duly elected representatives?
Another issue is personal privacy. The news media are real quick to jump around that by creating some connection -- true or false -- to an issue and thus the person is suddenly now a "public figure". Even if the circumstances were false to begin with, the news media go with that and print anything. Some of us value our privacy and don't have the resources to fight adverse publicity and lose our job, families, etc. If you're a genuine public figure they can really go to town on you.