Journalists should not protect their sources if they lie or fabricate information. Otherwise, it seems like the perfect loophole for committing slander and libel. Don't directly publish the information yourself, but instead convince a journalist to be a confidential source.

I think there is a pretty big line on the spectrum of "lying and fabricating," from reading/erasing a name on a report and lying about it to maintain anonymity (not morally blameworthy to an extent that the person shouldn't be protected, I don't think) and totally making up events to cast someone in a false light (very morally blameworthy). I don't think you can draw a bright line rule like "[j]ournalists should not protect their sources if they lie or fabricate information" because of this spectrum.