I normally rail against the citation of articles quoting anonymous sources, particularly from the major domestic news organizations. In this blessed land, anonymous sources are usually being either coy, abusive or mendacious. Coy in the sense that every informed reader of the news article knows who the source is. Abusive in that the source is a policy entrepreneur using the journalist's supposed autonomy as a shield for floating as a fact what is indeed only a proposition. Mendacious in that what is being said is flatly untrue, but having been published and incepted as a part of the detritus of discourse cannot be traced to any particular liar in government, the parties or industry.
Anonymous sourcing makes antennae up in the "stay alert, you are being manipulated" mode my default news reading and viewing position -- which is unfortunate.
However, there are times that the only way a tale can get told is when anonymous, protected persons spill the beans. The Reuters story on the politics behind JAL's decision to buy Airbus aircraft "Insight: Japan politics looms over ANA's choice between Airbus, Boeing" is one such tale. Nobody with a career or even just a job can offer details or comment upon the way passenger aircraft purchase decisions really get made. For that, one needs someone talking from behind a mask.