The right to protect sources is vital to a free press. If you look at the Obama admin seeking out and going after leaks, you can clearly see the chilling effect this has on officials willing to speak off the record. They took it one step further and went after the journalist who protected the source, threatening him with leaking national secrets. This will only further prevent journalists from digging deeper.
After all, they keep telling us, "why worry if you have nothing to hide"? as they erode our liberties more and more. Thanks to Snowden and other brave leakers, now we know the truth... there is no privacy, there is no security, and the NSA really is tapping pretty much everything. I'm not scared of foreign terrorists, or spy's. Time for some sunlight on the rogue agency's that have shredded the constitution and perverted the American dream.
It doesn't really matter how or where it is protected, it is the fact that it needs to be protected and should be protected. Journalists can not do their job correctly if they don't go out and get information and obviously people are not going to divulge this information if it puts their neck on the line. Shielding confidential sources is paramount in journalism and it is the only thing that guarantees the government will be more transparent.
No, a journalists right to shield confidential sources should not be protected by the First Amendment, because a person doesn't have the right to commit treason simply because they want to exercise their First Amendment right. If they speak to a journalist, they run the risk that they will ask the journalist who their source is. There's nothing wrong with that.